Iain takes us back to the swinging 60s to revisit the theft of a portrait that had been hanging in London’s National Gallery for just 19 days before it vanished.

At first, no one believes it’s been stolen – but when a handwritten ransom note arrives, detectives are forced to take the case seriously.

Iain uncovers how this case baffled police for years and eventually ended up inspiring a film starring Jim Broadbent and Helen Mirren!

Murder They Wrote with Laura Whitmore and Iain Stirling is available twice a week on BBC Sounds. Subscribe now so you never miss an episode. Got a case or story for us? Email [email protected].