MI5 in the Great War

by Nigel West

  It was proposed that all enemy subjects should be removed from neutral ships and detained until it was proved that they were not engaged ‘actually or potentially’ in any form of war endeavour prohibited by international law.

  It seems to have been falsely reported in March 1916 that the Germans had transferred the headquarters of their spy organisation against England to Stavanger in Norway and to be sending agents to England under cover of Norwegian passports on torpedo-boats transferring them to British trawlers mid-ocean. It was also said that German agents were procuring employment on Allied ships by producing Dutch certificates. Young Germans returned safely to Germany carrying Peruvian papers. In August two agencies for fabricating passports had been discovered in Rotterdam.

  In March the majority of suspects seemed to be coming from Spain and Greece, but a few still came from Holland and France. Measures were under consideration for limiting the number of British consuls abroad who had power to grant visas, and for keeping direct touch with these consuls so that all intending travellers to England might be dealt with on uniform lines. In this we would be copying the German system.

  An agent from Christiania reported that the Germans were providing excellent cover for their spies who were conducting genuine business in the fish trade, had proper bank accounts, were acknowledged and protected by the German Minister and could not be turned out by the police. The agent suggested that the British might adopt certain of the so methods, a plan that was agreed to by MI5 and a certain importer of Norwegian canned goods went to Norway for a time on their behalf.

  The Germans attempted to send in an agent as representative of a Swedish firm; this was met by a refusal to grant a visa unless the British firm wrote to say they desired a visit from the representative of the foreign house. But this they did not.

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  In June 1916, after the battle of Jutland, it was anticipated that German agents would he coming to this country to ascertain the damage done to His Majesty’s ships. A special warning was therefore issued to the police through the Home Office instructing them to interrogate severely all commercial travellers of alien origin arriving in any police jurisdiction with a view to obtaining precise particulars as to their business, length of service, pay, orders received, execution of such orders, etc., and if possible their answers were to be verified by reference to the firms which they had visited. In July 1916 MO5G caused a circular to be issued that the German government were recruiting circus-riders, music-hall artists and actors of the regular stage as agents, and asked that special attention should he paid to such persons and particularly at naval centres. In case of suspicion the strictest enquiry could be made under DRR 53 and if insufficient evidence was found to justify arrest under DRR 53, the particulars were to be reported and papers sent to the War Office; if the suspect moved, the Chief Constable of the district to which he was going was to be informed and asked to keep him under observation.

  Among the types of agents mentioned in the second half of 1916 was the case of an employee of the Putilow Powder Works at Petrograd who is alleged to have been in Hull during the battle of the North Sea and to have gone thence to Stockholm, where he gave to the correspondent of the Deutsche Allgemeine Zeitung all the information he had collected in England. There were other agents masquerading as nurses and supplied with Belgian nursing diplomas. Also, refugees from Belgium and Northern France, Belgians supplied with French papers and French with Belgian papers, and German agents masquerading as the crews of tramp steamers.

  In connection with this latter class of agent, the Foreign Office had issued a circular to the diplomatic representatives of neutral states calling attention to the negligence of consuls in granting certificates of nationality to alien seamen.

  In August 1916 a German agent of the Russian Secret Service reported that a special bureau was established at Rotterdam with the object of making detailed enquiries of all officers and members of crews of neutral ships. In order to obtain accurate reports of the damage done by Zeppelin attacks, neutral businessmen and engineers would be sent over two or three days before a raid to do genuine business in the part selected for the attack. On being referred to, ‘T’ had no knowledge of the bureau but stated that just before the last raid he had had to deal with a number of persons who wanted to go to England. These persons claimed to have been approached by German agents and to be willing to betray their employers without payment provided the visa for the journey were granted, and he suggested that in future persons of the class described should be held until enquiry could be made about them. In October the Germans did try to send in agents in preparation for a raid which did not come off and the question arose of holding up traffic from Holland and Scandinavia for twenty-four hours. It was however decided that the precautions already existing were sufficient.

  In Spain, the Germans were said to be collecting information with regard to the movements of ships and cargoes from insurance agents. Letters were received from North and South America written with a view to localising military units or to identifying military censor stamps for future reference. Such missives would appear quite harmless: either the address of an officer would be asked for or a friendly letter would be addressed by some group of schoolchildren to men at the Front. The policy followed with regard to letters about officers’ addresses was to wait for the answers and then after submission to DSI, either to retain them or return them to sender with an enquiry as to the bona-fides of the writer.

  DRR 22B had been issued requiring every person who makes a business of receiving for reward letters, telegrams, postal packets of any kind to register the address of his business and to keep a record of all packets so received. This register was to be open to inspection by the police.

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  In February 1915 all telegrams from the United Kingdom to neutral countries in Europe were being delayed twenty-four hours, yet spy messages were going through.

  In answer to a question from MO5A, it was stated that the basic principle of Cable Censorship was the withholding of facilities for trading with the enemy. MO5G then (presumably) pointed out that nearly all spy messages by letter or wire were couched in trade terms and that, in concentrating upon blocking commercial relations with the enemy the trade section of the Censorship had lost sight of the more important question of espionage. At this time the Dierks gang’s activities were under investigation and MO5A asked for drastic restriction of cables to America and to the Continent, but the interests of trade prevailed and in the end it was arranged merely to subject cables to North and South America to the same delay as those to the Continent.

  MO5 had failed in October 1914 to stop transmission of all cables not bearing the name and address of the sender, and in January 1915 to procure the name and address of the senders of all cablegrams submitted. But in June 1915 it was arranged that the A. forms of telegrams from certain post offices should be examined at the GPO’s investigation branch by persons with a knowledge of code and particular handwritings.

  The advantages claimed for this method were greater secrecy and power to judge the genuineness of a message from knowledge of national peculiarities in handwriting. Messages which the Chief Censor believed to defy detection as spy production were picked out by the GPO and their senders were put on trial.

  During 1916, the Postal Censorship was extended at home and abroad. Besides the inclusion of countries in south-east Europe already noted, which took place in April 1915, a warrant for the examination of mails to and from the United States and the states of South America was obtained in May and, as regards the United States, regular examination of the mails was enforced in December 1915 at the most urgent request of MO5G.

  Letters to and from PoWs were brought under regular examination in November, in which month also mails carried on neutral ships which voluntarily entered British ports became subject to examination. As previously noted, transit mails had been under examination since April 1915 and in October of that year it was stated that only in the transit ma
il did the enemy frankly and fully reveal the details of his business. Between 20 June and 8 October more than a hundred letters had been noted or photographed for containing codes for the evasion of Cable Censorship or other similar information. In April 1916 incoming mail to South and Central America was made subject to censorship and a warrant was obtained for the Japanese mail. In March 1916 the Cabinet authorised the examination of letter mails carried by neutral ships which had been ordered into port from the high seas.

  The letters submitted to MO5G during this year belonged to the categories of peace propaganda; Independent Labour Party pamphlets, seditious literature; letters relating to possible enemy agents; letters infringing DRR 18B, such as those dealing with patent specifications, and inventions were also submitted from December onwards.

  Early in 1916 MO5G directed that all indiscreet letters containing useful information, with the exception of those that were suppressed or returned to sender, should be submitted, and also all letters in the American mail indicating the locality, movements or activities of German agents. So large a number of worthless letters had been received that it was necessary to define strictly what was of value; on the other hand in censoring the Irish mail it became evident that evasion was taking place since no letters for persons on the general Black List were intercepted.

  In June 1915 under DRR 22A it was made an offence to possess codes and ciphers unless the possessor could prove they were harmless; he was also to produce the key on requisition.

  The sending of picture postcards etc., was prohibited as also the despatch of newspapers except by newsagents and publishers under license. Arrangements were made with The Times that the names and addresses of all advertisers should be given and that any doubtful cases should be reported to Scotland Yard, and a recommendation was submitted that similar precautions should be taken in the case of other newspapers. MO5G noted that no spies had been detected under these measures but many advertisements had been refused or else referred to the police for enquiry.

  In connection with the seizure of official reports sent to directors of the Zeeland Company, G suggested that official reports or debates on topics of military interest should not be sold during the war or that indiscreet speeches in the House should be censored before publication. The use of invisible ink or of secret means of communication was made illegal and subsequently the use of all code was prohibited.

  In July 1915 it was arranged that the Censor’s Office should carry out all tests for secret writing and code and thus decide whether action by MO5 was necessary. As a rule letters containing code or secret writing were to be photographed but in case of emergency the missive was to be transmitted at once to MO5. In testing, factors regarded as suspicious were blank sheets of paper, blank postcards, unduly large spaces between the lines, arrangement of postal stamps, marks, crosses, dots indicating that a secret or code message is involved.

  Drastic methods were employed to discover scratches and damage done to the surface of the paper. At that Censor’s request, G Branch agreed to keep that department informed of the value attached to the letters submitted. No differentiation was to be made on the lists but in really secret cases the Censor was to receive a separate warning.

  In July and August 1915, special measures were adopted with regard to the PoW correspondence with a view to prevent their sending messages in secret ink. Instead they were to use only highly glazed paper, soft pencil and ungummed envelopes; the despatch of picture postcards, drawings and embellishments of any kind was prohibited. Outgoing parcels from PoWs were delayed so that they could not reach the nearest German agent within a week of their despatch.

  Special measures were taken with regard to envelopes stamped ‘On His Majesty’s Service’. Such envelopes were never forwarded by post but always by Foreign Office bag, yet some had been seen in the office of the German consul-general at Rotterdam. Censors were therefore instructed to open all such letters. It may be noted that various attempts were made to obtain envelopes stamped by Allied governments. The mails to Holland, Denmark and Norway were of chief importance from the point of view of counter-espionage. Writing about the Scandinavian mail, MO5 stated that six convicted spies had corresponded with Norway and Sweden and that, as Holland had been rendered less suitable as a German espionage centre, it was to be expected that Scandinavia would play a greater part. In a general report on the value of the Postal Censorship, MO5G said that it had assisted directly or indirectly in ten out of twenty cases of enemy agents dealt with since the outbreak of war; it had prevented leakage of information, supplied links between suspected persons, thrown light by German propaganda, and helped to locate enemy agents in foreign countries.

  The whole question of how to prevent information being conveyed out of the country was discussed in a G paper of January 1916. Messages were conveyed by post, wire or persons: as regards letters, it was not considered probable that much use would be made of so slow and risky a method, although code might readily escape detection by an inexpert censor. On the other hand, while nearly all the wires submitted looked suspicious, it was unlikely that really dangerous messages would give this impression. The difficulty of detecting code in wires diminished greatly when the address was a known spy address, but in other cases, knowledge of the address and status of sender and addressee did not suffice, the only safeguard was to investigate the bona-fides of the sender before despatching the wire. Other possibly fruitful methods were to scrutinise wires to neutral countries bearing addresses of more than usual length or addressed to firms and individuals whose names did not appear in directories, and all wires to a particular town on a particular day.

  The report’s author considered that insufficient measures had been taken with regard to carriers. Carriers would either report verbally or convey documents secretly. Regarding carriers of verbal messages, it was suggested that thorough enquiry be made about all persons constantly crossing the sea; and in all suspicious cases co-operation be maintained with a British ‘C’ agent in Rotterdam; also, more thorough investigation be made by MO5G before granting the permit; and, as regarding carriers of documents, that a more thorough search be made of constant travellers and great care be exercised in case of a find so as to collect evidence that would convince a judge and jury.

  Various methods of conveying information out of the country came to light in the winter of 1915-16. Spies were sending messages in invisible ink enclosed in envelopes addressed to Belgian and English PoWs and marked in some way recognisable by the German Censor who forwarded them to the proper quarter.

  The British Postal Censor was asked to test letters addressed to British PoWs in Germany with the same stringency as was applied to ordinary correspondence. It was reported from an unguaranteed source that letters of a harmless nature would be posted in England for the United States of America, there steamed open, fresh messages inserted, and the envelope posted back to the original sender. In 1917 the Censor carefully examined all returned letters from the United States of America.

  Parcels of suspiciously marked ‘magazines’ were being sent to PoWs and the opinion was expressed that old books should not be allowed through to enemy countries without careful enquiry into the bona-fides of the senders, as documents and papers of an undesirable nature were being sent abroad. From a Dutch newspaper, the Telegraaf, it was already known that code advertisements containing news of the movements of British ships were being inserted in the ‘Servants Wanted’ columns of the press, and these were wired to Berlin as soon as the English papers reached Holland. News was carried abroad by various methods, sometimes on a slip of paper inserted between the sides of a matchbox and on the back of the paper covering the box; in books, periodicals, newspapers and on banknotes – these things being carried ostensibly for use of the journey; in shaving brushes with screw-tops; stamped on the skin of a Belgian woman; on toys carved by German PoWs; concealed in slabs of chocolate, etc. Other means employed were messages on gramophone records concealed in a case marked ‘Glass’
directed to a cover address, but destined for a former Belgian official, Joseph de Bueger; concealed on board a ship with the connivance of the mate.

  In July 1916, owing to a report from Copenhagen, a system was discovered of smuggling goods and letters from Germany to America and vice versa. The smuggling agents were a checker on the piers and a landing agent at New York. They received £20 per packet of mail delivered in New York or Copenhagen. Hugo Schmidt, the representative of the Deutsche Bank in America, received the letters in New York.

  Messages were said to be carried in the following ways: hollow sticks carried by repatriated prisoners of war; the backs of luggage and hotel labels; every article of clothing and adornment; parts of the body and mock wounds, bandages, etc.; fountain pens, cigars, pipes; articles of food; invisible writing on wrappings of parcels and linen; mnemonic notes on printed matter carried for the journey; photographic plates and films not developed; gramophone and phonograph records; and carrier pigeons. The methods of countering such illicit carrying were restrictions on travel and careful searches at the ports, but in practice this was difficult unless the person had been signalled in advance. Even the ordinary search of correspondence and papers carried by passengers necessitating the scrutiny of small bits of paper, scribbled notes, addresses and figures on the margin of business papers took so much time that the Home Office suggested carrying out the examination in London – a stop which would completely have nullified all efforts to stop letter carrying.

  Papers might also be concealed in heavy luggage which would escape search at the ports. The difficulty of meeting this danger was to find an authority that had both time and power to conduct the search. Another much used method was by abuse of diplomatic privilege. During July 1916 the right to carry diplomatic despatches under privilege was restricted to official couriers of the diplomatic service, and unofficial persons carrying despatches were subjected to the same inspection as ordinary passengers. But diplomatic official couriers themselves were so suspect that in October the French government agreed to present them from travelling by the Folkestone and Boulogne route.