In January 2013 on Morecambe beach, Ken Wilman and his dog Madge found something they believed to be ambergris - an extremely unusual, rare and valuable product of sperm whales. What happened next turned Ken's world upside down.
Overnight, the story hit the international news with excitement at the prospect of a happy financial outcome for Ken. But things turned out not to be so straightforward.
Peregrine Andrews followed the story from the beginning - and he discovered that authenticating and selling one of the world's most mysterious substances is far from easy.
Produced by Peregrine Andrews
A Falling Tree production for BBC Radio 4.