Declassified East German Report Reveals KGB Knew About 1955 Berlin Spy Tunnel From the Start

A senior East German police officer found a report on a Cold War spy tunnel in the chaos after the fall of the Berlin Wall, took it home and kept it for decades before donating it to the Berliner Unterwelten museum. The museum specialises in the city’s extensive warrens of underground facilities. The document has now been published for the first time.

In 1955 the British and American intelligence services dug a 550m tunnel into the Soviet sector of Berlin. The tunnel was used to tap into USSR communications cables for 11 months before the operation was revealed to the world in April 1956. The British Secret Intelligence Service called the operation Operation Stopwatch while the CIA called it Operation Gold.

The wiretap delivered about 40,000 hours of taped conversations and 90,000 messages. The intercepted material revealed Nikita Khrushchev’s secret denunciation of Stalin and made it clear that the USSR had no serious intention of invading western Europe.

It purportedly enabled the identification of a hundred Warsaw Pact military bases, 350 spies from the Soviet GRU and several thousand Red Army officers.

Helmut Müller-Enbergs, a German intelligence historian and co-author of the book Operation Gold: the Berlin Spy Tunnel, said the operation was comparable to the achievements of Bletchley Park. “The source was extremely important,” he said. ” The CIA eventually published a handful of cursory reports on Operation Gold but kept most files heavily classified.

Researchers later found several other papers on the tunnel in the archives of the Stasi. MI6 and the Russian secret services have remained completely silent on the subject. The newly released document is the only surviving copy of a damage assessment compiled for the GDR’s interior minister in the weeks after the tunnel was exposed.