The bounty is part of plans to supply up to 50,000 people with cameras in order to search for the mythical sea creature at next weekend's Rock Ness music festival.

Organisers are claiming it will be the largest ever organised attempt to prove the famous monster is real.

Bookmakers William Hill are offering the reward to anyone who finds evidence which persuades the Natural History Museum that Nessie exists.

They are also offering odds of 250/1 that the museum will agree the existence of the creature sometime this year.

William Hill spokesman Rupert Adams said: "We are hoping the £1 million bounty will help to solve one of the great enigmas of modern times.

"This is a great opportunity with such huge crowds on the shores of Loch Ness and it will be fantastic if someone can get a picture with one of the thousands of Nessie-Snappers cameras we are handing out, that can rival the 'Surgeon's photograph', which is still the most recognised despite being taken over 50 years ago."

The bookmakers are also offering a number of consolation prizes including £1,000 and a free £250 bet for the best photographic evidence real or staged.

To qualify for the reward all evidence must be gathered over the weekend of the two-day music festival and must be submitted to William Hill by Monday June 18.

The festival, at Dores, near Inverness, is on June 9 and 10 and features top bands such as the Manic Street Preachers.