The Royal Navy said it is investigating claims by an Italian diver that a long-lost wreckage of a British submarine has been found with the bodies of its 71-strong crew still inside.
Italian scuba diver Massimo Bondone told local press he has discovered the HMS P311, thought to have been downed in 1942, off the northeast coast of Sardinia.
The vessel disappeared after leaving Malta in December 1942 to take part in Operation Principle, an Allied attack on Italian warships off the coast of the Mediterranean island.
Mr Bondone said he found the wreckage at a depth of 80 metres (262ft) off the isle of Tavolara and knew it was the British vessel as he approached it with his team.
He said the 71 crew members were still inside the vessel and probably died as a result of suffocation.
"It looks like she probably went down with air sealed inside, meaning then crew eventually died of oxygen deprivation," he told La Nuova Sardegna newspaper.
A Royal Navy spokesman said: "We are examining our records to determine whether or not this is a Royal Navy submarine."
A spokesman told The Local that the wreckage would almost certainly not be moved irrespective of whether bodies were concealed inside.
What do we know about the P311?
The P311 was lost between December 30, 1942 and January 8, 1943 when she was reported missing after failing to return to base.
She was en route to La Maddalena, Sardinia, to attack two Italian gun cruisers as part of Operation Principle.
Her last signal was sent on December 31, 1942 and she is believed to have been sunk by Italian mines on or around two days later.
The T-class submarine, fitted with two Chariot manned torpedoes, was the only vessel in her class never to be given a name.
She was due to be called Tutankhamun, after the Egyptian pharaoh, but was lost before she could be officially named.
None of the vessel's 71-strong crew - including its highly decorated commanding officer Commander Richard Cayley - were ever found.