The Portland Spy Ring: Espionage During the Cold War

The Portland Spy Ring was a group of five spies working undercover in the UK and operating secretly with no diplomatic cover from the KGB and the USSR. However, the Portland Spy Ring passed the information they gained onto Soviet forces.

Portland Spy Ring
(Img; The Kroger’s bungalow which acted as a communications hub for the Portland Spy Ring; via BBC News)

So What?

Remarkably, the Portland Spy Ring was able to operate for many years without detection. Whilst the exact number of documents shared by the Portland Spy Ring to Soviet forces remains unknown, MI5 now estimates that the Portland Spy Ring illicitly shared in excess of 350 highly sensitive naval documents with the KGB.

Most think that the intelligence gained by Soviet forces from the Portland Spy Ring ultimately informed Soviet manufacture of much more efficient submarines and naval technology. The Portland Spy Ring therefore tangibly changed the course of the Cold War – the group aided the Soviet government to further their technology programmes, as well as further their understanding of UK naval capabilities.


The members of the Portland Spy Ring are as follows:

  • Harry Houghton – Houghton had worked in the Royal Navy during WW2, and then was a clerk to the British Naval Attaché in Warsaw. Later, authorities moved him to the Underwater Weapons Establishment in Portland, UK. Polish Intelligence recruited him as a spy in the 1950s, and then passed him onto Soviet Intelligence.

  • Ethel Gee – Gee worked as a filing clerk at the Underwater Weapons Establishment in Portland, UK. Gee was colleague of Houghton, and she had access to material of higher classification than Houghton.

  • Gordon Lonsdale – Houghton and Gee’s contact; Lonsdale collected information supplied by them and would courier the documents to the Korgers’ home. Authorities then send this documents to Moscow.

  • Helen Kroger – Helen Kroger married and lived with Peter Kroger. They had been working undercover as booksellers, but had actually been sending material collected from Lonsdale back to Moscow. Her real name was Lona Cohen.

  • Peter Kroger – Married to Helen Kroger. His real name was Morris Cohen.
Portland Spy Ring
(Img; Harry Houghton and Ethel Gee; via BBC News)

The Portland Spy Ring existed to gain information about British naval capabilities during the Cold War. As a result, the operation lasted from the early 1950s until 1961.


Harry Houghton, whilst working for the British Embassy in Warsaw in 1952, was recruited to sell British classified documentation to the Polish Secret Service. Later, Polish forces passed him on as a contact to the KGB on his return to England.

Gee had access to documentation of a higher classification than Houghton whilst they were working at the Underwater Weapons Establishment in Portland. However, she was a low-paid clerk for the Portland Underwater Weapons Facility. Additionally, she was in love with Houghton, and the two had an affair. As such, she was easy for Houghton to recruit to assist with his illegal espionage activities. As a result, they developed a system wherein Gee would steal and hide classified documents on her person to bring them to Houghton. Houghton would then photocopy these documents.

Houghton would either travel alone or with Gee to London, wherein they would meet his contact, Lonsdale. Lonsdale would then intercept documents and provide Houghton and Gee with payment for their service. This was sometimes cash, but also sometimes other incentives such as play tickets.

Portland Spy Ring
(Img; Gordon Lonsdale’s fake Canadian Passport. His real name was Konon Molody; via the Science Museum)

Lonsdale would then courier the documents to Kroger’s house in Ruislip. Helen and Peter Kroger were deep undercover, under fake identities and the ruse of working as bookkeepers. However, their acted home as the communication hub for the Portland Spy Ring. The Krogers would send document copies to Moscow.

The scale of this espionage ring is unknown to this day, however, Loughton estimated that between January and November 1952 alone, the Portland Spy Ring passed 99 secret documents, including a Manual of UK Naval Intelligence, to the USSR.


The initial tip-off to British Intelligence forces with regards to the Portland Spy Ring was from a CIA agent working within Polish intelligence. In 1960, the CIA officer, Michal Goleniewski, reported to MI5 that Polish Intelligence had recruited an agent in the British Naval Attaché in Warsaw, but the agent had since returned to Britain. This agent was Houghton.

As a result, MI5 monitored members of the Portland Spy Ring closely in undercover surveillance operations. In the early stages of the investigation, MI5 undercover agents followed Houghton and Gee on one of their many trips to London. They noticed that they had met with a then-unknown man, who was at the time “an illegal agent working for either the Russian or Polish intelligence service”. Time after someone revealed the man was Kolon Melody, operating under the identity of “Gordon Lonsdale”.

Following further surveillance on Houghton and Lonsdale, MI5 were able to trace Lonsdale to the home of Peter and Helen Kroger in Ruislip.

Finally, MI5 felt they had enough evidence to proceed with the arrests of the Portland Spy Ring members. Houghton, Gee, and Lonsdale were all arrested in London during one of their meetings in 1960. All three were in possession of classified naval documents. Simultaneously, MI5 raided and arrested the Krogers in their home. During the raid of their home, Helen Kroger excused herself to put on the boiler, but in fact was found trying to destroy evidence of microdots.

The Krogers’ home contained radio technology which they used to communicate with Moscow, as well as multiple fake passports and hundreds of classified documents.


The Portland Spy Ring were subsequently trialled and convicted in 1961. All five were found guilty on espionage charges.

Portland Spy Ring
(Img; Peter and Helen Kroger – whose real names were Morris and Lona Cohen – were later commemorated on Russian stamps; via robslondon)

Both Houghton and Gee were tried and sentenced to 15 years imprisonment each. They married in prison and were eventually released in 1970. Lonsdale and the Krogers were all exchanged in prisoner swaps with Soviet prisoners held in London before serving their full sentences.


The Portland Spy Ring were able, through prior connections with each other and previous experience in espionage, to successfully steal and transmit large volumes of classified naval documentation for KGB use. The Portland Spy Ring provides an interesting example of how extremely effective clandestine operations were during the Cold War: just five people were able to steal hundreds of highly classified documents and pass them onto the UK’s direct adversaries.

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