The net tightens as police arrest George and Layton and search their homes. But when the missing treasure is nowhere to be found, investigators start to wonder: is the hoard even real?

Meanwhile deleted photos offer a new lead.

Narrator: Aimee-Ffion Edwards

Contributors: Tim Hoverd, Nigel Cleeton, Peter Reavill, Simon Wicks, Gareth Thomas, Dr Gareth Williams, Kevin Hegarty KC

Sound Design: Peregrine Andrews

Production Co-ordinator: Dan Marchini

Associate Producer: David James Smith

Producer: Aron Keller

Exec Producer: James Robinson

A BBC Studios Audio Production