British intelligence agencies reportedly spent over 20 years investigating a suspected Russian double agent embedded within MI6, only to close the case without finding concrete evidence. According to The Guardian, which cited unnamed sources, the high-stakes probe — codenamed Operation Wedlock — ultimately ended “inconclusively,” and the suspected officer quietly left the service.
The investigation, believed to have run from the mid-1990s until around 2015, was spearheaded by MI5, the UK’s domestic counter-intelligence agency, after a tip-off from the CIA raised alarms about potential Russian espionage at the heart of Britain’s foreign intelligence service.
“[We were told] the target was a Russian spy… The US believed he was leaking information to the Russians,” a source familiar with the case told The Guardian. The operation was reportedly treated with extreme urgency and seriousness. “Wedlock eclipsed them all,” the source added, describing it as more significant than any other case MI5 had handled.
Involving up to 35 officers at its peak, the secretive operation deployed surveillance tactics typically reserved for the most serious national security threats. MI5 allegedly bugged the suspect’s home, tracked his movements across London with video surveillance, and even followed him on trips abroad — despite operating outside its legal jurisdiction in doing so. Intelligence officials reportedly suspected the mole had two collaborators based in London, though no evidence emerged to support that theory.
“We thought we had another Philby on our hands,” one source said, referring to Kim Philby, the infamous British intelligence officer who spied for the Soviet Union as part of the Cambridge Five during the Cold War.
Despite the intensity and scale of the operation, which spanned two decades, MI5 failed to obtain any proof of espionage. By the time Operation Wedlock was wound down around 2015, the individual under suspicion had already left MI6. “MI5 never got the conclusive proof it was looking for,” a source admitted, calling the mission “highly unusual… the longest in recent memory and probably the most expensive.”
The case highlights long-standing concerns in the UK about Russian intelligence activity, especially amid a history of allegations without publicly released evidence. Notably, in 2018, the UK accused Russia of attempting to assassinate former Russian military intelligence officer and MI6 asset Sergey Skripal and his daughter in Salisbury — claims the Kremlin denied.
Tensions between London and Moscow have further deteriorated since the escalation of the war in Ukraine in 2022. The UK remains one of Kyiv’s most vocal supporters, providing military aid and imposing sanctions against Russia. Russian officials, in turn, have accused British intelligence of actively training Ukrainian units for sabotage operations within Russian territory.
