How did a film, presented by a dubious producer based in London and purporting to show an autopsy being performed on a dead alien, come to convince large parts of the UFO-hungry public that it was authentic? Why did his reluctance to have the film authenticated and his string of broken promises not raise alarm bells? What's the real story behind a hoax that travelled the world.

According to folklore a large sea monster lurks in depth of Loch Ness in Scotland. Over the years, grainy photographs and inconclusive video footage has emerged to keep the legend alive. Is it a clever hoax or the real thing?

An inadvertent hoax perhaps? Or a very clever ploy that made an unknown 23 year old New York City radio producer famous overnight? Either way, Orson Welles's infamous broadcast adaption of the HG Wells story on Halloween 1938 sent America into a tailspin as millions became convinced that Earth really was being invaded by aliens from Mars.

This is one of the great hoax-or-not hoax stories; the best-selling book by Henry Charrierre, which told of his life on the Penal colony island of French Guiana was 'exposed' as a novel, not a biography, by Gerrard de Villiers in 1970. The historical sub plots to this fascinating episode are the harsh - some say inhuman - conditions on Devil's Island which gave birth to the book.

The endless quest to conclusively connect man with the ape seemed to have come to an end in the year 1912 with the discovery of a skull and jawbone in a quarry near the small village of Piltdown in Sussex. The scientific and academic world went into a frenzy.