A man was stunned when he discovered a ‘confidential’ operation manual for a US Navy aircraft carrier nuclear reactor – washed up on a beach.

Ian Le Breton was walking his dog when he discovered the manual’s cover headed with a warning of ‘confidential’ and ‘restricted data.’

He initially thought it may have been a relic from the Second World War and stored it in his shed.

But he was stunned after carrying out some research to discover it was from a nuclear reactor that powers the biggest warships in Navy history.

Ian Le Breton was walking his dog and beachcombing on Jersey when he discovered the cover of a classified US Navy nuclear manual. (SWNS)

It is also marked NOFORN that stands for no foreign nationals; a term still used today by the US government when describing classified information.

There is no indication how or when it ended up in British waters but it was suggested it may have been thrown overboard or ended up in the wrong rubbish bin.

Ian, 59, of Rozel in Jersey, has now posted pictures of his find on Facebook.

Two A4W/A1G reactors power each of the US Navy’s 10 Nimitz class carriers – the biggest warships ever built.

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The 332.8 metre long vessels weight 100,000 tonnes each, have a 4.5 acre flight deck capable of carrying more than 60 aircraft and can carry around 3,000 ship’s company, 1500 air wing and 500 other crew.

Ian, a retired customs and immigration official who has four grown up children, said several people who have seen his post said they were pursuing the matter with contacts in the US Navy.

He said: “It is impossible to say if it is still in use. The regulations it refers to were created in 1954 so it is from sometime after that.

“By the corrosion on the metal I would say it has been in the sea for a number of years.

“It is well corroded and smudged – but although it has clearly been knocked about it it is not particularly worn.

“Having looked at it again there is no indication that there was any need for it to be in waters in this part of the world during any recent activities so it must have travelled a long distance.

“I can’t imagine one of these carriers just popping into the English channel.”