By the 1970s Howard Hughes was the "invisible billionaire”. A business tycoon, a daring aviator and Hollywood Lothario, Hughes had an amazing life story... but hiding away in luxury hotels he wasn't sharing his memories with anyone.

Then the recluse told a respected publishing house - via intermediaries - that he was working on an autobiography. The book would be a blockbuster... only it was all a lie.

For a full list of sources go to timharford.com