A scientist claims he has cracked the secret of the Loch Ness Monster's identity - she was really a circus elephant having a bath.

The myth of a massive wild beast living in the Scottish lake was sparked by the first modern "sighting" in 1933.

Since then eyewitness accounts and fuzzy photographs of a creature with a long neck and humps have fuelled the debate over the animal's existence.

However, Neil Clark reckons he has finally cracked the mystery - and that it was nothing more than a clever piece of marketing.

Dr Clark, curator of palaeontology at Glasgow University's Hunterian Museum, says circus owner Bertram Mills saw an opportunity to generate massive publicity when one of his elephants was swimming in the loch.

He reckons Mr Mills was inspired to invent the myth by the way the creature's back and trunk looked like the hump and neck of a monster when they emerged from the water.

Mr Mills offered reward of £20,000 - £1m in today's money - to anyone who could capture the "monster" in 1933.

And Dr Clark pointed out several sightings, usually of a large, grey creature, were made in the years immediately afterwards.

"It's not surprising Bertram Mills offered a £20,000 reward to anyone who could capture the monster for his circus," Dr Clark told The Times.

"He already had the Loch Ness monster in his circus."