Historians and television crews have returned to the Arctic Circle in the latest attempt to find a British midget submarine lost in an attack on the Tirpitz 60 years ago.

HMS X5 was sunk in September 1943 during a daring raid on the pride of the German Fleet at anchor in Kaafjord, near Tromso, in northern Norway.

Tirpitz was badly damaged, but not mortally wounded, by the raid – codenamed Operation Source – but the fate of X5 has always been somewhat unclear.

It is thought most likely she was destroyed after breaking the surface of the sea about 650 yards from the battleship.

Intensive fire from flak guns was directed against the midget submarine, before destroyers pounded the spot with depth charges.

What has never been established is whether X5 had accomplished her mission and fixed limpet mines to Tirpitz’s hull.

Other craft in the raiding force certainly succeeded; the battleship was knocked out of action by the attack for more than six months.

“To get as close as she did remains a major accomplishment,” said RN Submarine Museum archivist George Malcolmson.

“Some sources suggest that X5 had attacked Tirpitz and was leaving, most say that she had not yet attacked. Whichever is correct, the boat was literally hammered by gunfire and the whole wreck site plastered by depth charges and bombs.”

A BBC documentary team is producing a programme to mark the 60th anniversary of Tirpitz’s destruction – the RAF finally succeeded in sending her to the bottom in November 1944.

Stuart Usher, who works for the Defence Logistics Organisation, joined the BBC-led expedition, having been on two previous searches for X5.

“The documentary team asked if I’d like to join its search for X5. Some offers are just too good to refuse,” he said.

“We started a short distance from the scene of the attack in a nearby church yard in Kaafjord, where there’s a memorial which lists all those lost on Operation Source.”

But you will have to wait until the documentary is broadcast in November to learn whether the divers found the wreck.