The Sun: Secret plans from HMS Anson nuclear submarine found in British pub toilet

Classified files on £ 1.3 billion HMS Anson had been dropped in The Furness Railway in Barrow, Cumbria.

A source said: “It was lucky a Russian spy didn’t find them.”

The files showed the inner workings of the ­torpedo-loaded vessel, The Sun reports.

Key detail on HMS Anson’s hydraulics, which control torpedo hatches, steering and buoyancy, were in the dossier.

It was found in the boozer with a Royal Navy lanyard from the new £1.3 billion vessel.

A source said pub was packed when the papers, marked Official Sensitive, were found on Saturday night.

Government guidance says ­that information marked “Sensitive” must only be shared on “genuine need to know” and could have damaging ­consequences if lost, stolen, or ­published.

Former sub captain, Commander Ryan Ramsay said: “It looks like someone has taken the pages off the boat to study.

“They are part of a book that cover all the systems on a sub.

“When they do their basic submarine qualification they have to walk round the boat to demonstrate they know all the systems.