New images from the depths of the Loch Ness, in Scotland, have sparked fresh theories that Nessie the monster is lurking there.

A sonar reading of the freshwater loch, in the Scottish highlands, detected a distinctly-shaped outline towards its bed.

The unidentified shape was picked up by sonar equipment aboard a Jacobite Cruises vessel and follows reports the fabled monster had been seen in satellite images of the area.

Skipper John Askew told The Mirror: "This image certainly grabbed our attention.

"The Jacobite Queen spends every day sailing up and down the loch with the sonar on and this reading is the most unusual we have seen for quite some time.

"It's impossible to tell what we've picked up here, but along with those satellite images, you can't help feeling that reports of the Loch Ness Monster's demise may be premature."

Loch Ness
The 1934 \'Surgeon\'s Photograph\' sparked interest, as well as hoaxes, surrounding the existence of the Loch Ness monster Getty

Critics have dismissed the myth, noting how sightings usually occur before the summer season starts, when up to 100,000 tourists flock to the picturesque loch.

Nessie swam to the world's attention in 1933 when myths of the monster started becoming popular.

There have been dozens of reputed sightings of the beast with the most popular traits associated with it including it having a long tail, moving slowly and having a long neck.

The most famous alleged glimpse of the monster came in 1934 when Dr Robert Kenneth Wilson shot "Surgeon's Photograph", which supposedly showed Nessie's head and neck and was published in a newspaper in April 1934. However, it was later proved to be a hoax.