Loch Ness 'monster' found by Norwegian scientists

An underwater robot mapping the depths of Loch Ness has found a "monster", but not the lake's mythical creature.

Norwegian scientists from Kongsberg Maritime instead came across an enormous prop of the leviathan used for a 1969 film, the BBC reports.

"We have found a monster but not the one many people might have expected," Loch Ness expert Adrian Shine said.

The 9m-long likeness of the monster was made for the film The Private Life of Sherlock Holmes but sank during filming and was abandoned.

Sonar images of the prop clearly show the monster's characteristically long neck.

The images have drawn interest from around the world with the lake's mythical creature an ongoing source of fascination. 

Kongsberg Maritime was using cameras and sonar equipment to map the lake when the discovery was made.

The survey also uncovered a sunken boat and evidence the loch may be deeper than previously thought.