The discovery of a World War I German submarine off the Scottish coast has thrown light on one of the greatest mysteries of the conflict: Did the Loch Ness monster attack a U-boat?

Engineers from Scottish Power carrying out survey work for an undersea electricity cable pinpointed the wreck on the seabed off the coast of Dumfriesshires in eastern Scotland.

Subsea images reveal the vessel is largely intact and the discovery has prompted historians to investigate whether it is UB-85, whose captain claimed it was attacked by a grotesque sea monster in April 1918 before surrendering to a British warship.

A photograph taken by a British surgeon in 1933 of a strange creature in Loch Ness, central Scotland. (Photo: AP).

Official records state the submarine, like the one featured in our archive video, was spotted on the surface by HMS Coreopsis which sunk the U-boat after the Germans surrendered and were taken into captivity.

However, additional details which have since passed into folklore and are widely shared online have since emerged.

A subsea sonar image of the submarine wreck discovered off Scotland. (Photo:ScottishPower)

The legendary sea tale recounts how the U-boat commander, Captain Krech, told his captors during questioning that while his vessel was cruising on the surface to recharge its batteries crew members spotted a “strange beast” rising from the ocean.

According to the German commander, it had “a small head, but with teeth that could be seen glistening in the moonlight”.

Krech is believed to have declared that the creature’s enormous size caused the submarine to suddenly list to one side. The panicked Germans on deck started firing at it with their sidearms until the beast dropped back in the sea.

After the tussle, damage to the vessel’s forward section stopped it from diving and made the U-boat an easy target.

The British patrol boat HMS Coreopsis which captured the German crew in 1918. (Photo:Imperial War Museum, UK).

“That is why you were able to catch us on the surface," Krech is said to have told British naval officers.

Although Loch Ness is in central Scotland and more than 500 kilometres from the submarine wreck site, monster hunters have been quick to react, reports the Herald Scotland .

Gary Campbell, keeper of the Official Sightings Register of the Loch Ness Monster, said: “It is entirely feasible that some large sea creature disabled the submarine”.

"History has shown that there have been consistent reports of large ‘monsters’ not just in lakes and lochs like Loch Ness but out in open waters as well."

However Peter Roper, a spokesman for ScottishPower, was more restrained.