British media claim that the UK’s MI6 spy agency has managed to smuggle out secrets about upgrades to Russia’s strategic supersonic bombers with the help of the United States’ CIA and Israel’s Mossad.

The report, which emerged in UK media on Sunday, alleged that the stolen military secrets were about the newest version of Russia’s Tupolev Tu-160 (NATO code name Blackjack) strategic bombers.

The Daily Mail reported on Sunday that the spies had hidden the secret information in a packet of loose leaf tea aboard a Blackjack bomber (the same aircraft that MI6 wanted to learn more about) traveling to Venezuela.

According to the report, the packet of loose Russian Caravan tea was unknowingly taken by Russian pilots on board one of the two Blackjacks that were sent to Caracas last December to conduct drills with the Venezuelan Air Force.

When the plane landed at Caracas’ Simon Bolivar airport, an agent retrieved the discarded box of tea and then took it to a CIA officer waiting at a hotel in Caracas, the report said, adding that the secrets were taken to the US for analysis before being shared with UK and NATO forces.

Russian Air Force personnel stand in front of a Tupolev Tu-160 strategic "Blackjack" long-range heavy supersonic bomber aircraft upon landing at Maiquetia International Airport, just north of Caracas, on December 10, 2018. (Photo by AFP)

The report does not clarify how the secrets were stored in the tea consumed by the pilots and whether a memory device was used.

There has been no official reaction to the report, but Russian media have said the story sounds more like a plot from a spy novel than an actual intelligence operation.

The UK and Russia have been engaged in a diplomatic dispute after a former Russian double agent, Sergei Skripal, and his daughter were poisoned with the nerve agent Novichok in Salisbury in March 2018.

London blames Moscow for the attack, an allegation Russia strongly rejects.