The unbelievable story behind the Loch Ness Monster, and how the search for it has attracted people from across the world for decades. From Japan, the US and across the world, people were drawn to a remote, cold lake in the Highlands of Scotland.

World War II veterans getting the boys together for one last adventure, mad scientists and hippies all competed in a search for what they passionately believed would be the natural history discovery of the century – capturing evidence of the Loch Ness Monster.

Rumours and sightings of a dinosaur-like creature had persisted at Loch Ness for decades, and the 1970s was the peak decade of monster hunting. No qualifications were required to join the hunt, just a sense of wonder. Anyone could roll up at the banks of Loch Ness, take out their camera and declare they were joining the hunt for Nessie.

There was a well-organised official hunt – the Loch Ness Investigation Bureau – which placed vans and cameras around the Loch and watched it nonstop, but they came up with very little evidence.

There was the International Loch Ness Monster Search Party, led by Japanese pop promoter Yoshio Kou, who declared that he wanted to capture Nessie and take her round the world.

And then there were men such as Frank Searle, a cockney ex-soldier who lived by the Loch and who captured some astonishing photographs of the creature.

Over the years, monster-detecting methods changed – first it was all about sightings, then photographs, and eventually sonar and underwater cameras. Dr Robert Rines, of the Academy of Applied Science, brought a team of 'super-geniuses' to the Loch every summer, and they captured some incredible images of a huge flipper and possibly the face of Nessie. Even David Attenborough declared that photos such as the ones captured merited further investigation. However, the deeper they looked, the darker it got.

Monster egos, fakes and frustrations, rivalries and ridicule all meant that Loch Ness quickly became home to a very different type of beast. As picture after picture were exposed as fakes, the scene at Loch Ness became fraught. Lone wolf Frank Searle, in particular, became angry and dangerous. In the early 1980s, Frank was accused of throwing a petrol bomb at another group of Loch Ness researchers which ignited on the shore. He sprayed graffiti on the hallowed walls of Urquhart Castle that called another monster hunter a con man. Then, without warning, Frank Searle disappeared. His caravan was pushed into the Loch, and there were rumours that he had been killed...