A phone call from the police out of the blue. You want to help. Who wouldn't?

Scam Secrets returns with the chilling story of an audacious scam that reached all the way to the doorstep of its victims.

Jane and Neville were so convinced they were part of a police operation that they handed over their life savings - more than £670,000 - to criminals behind a scam known as courier fraud.

Fraud investigator Shari Vahl, criminal language expert Dr Lis Carter and former criminal Alex Wood analyse the tactics used - the fake emergency call, the mind games and the relentless contact - to lift the lid on how the criminals did it.

Along with guest expert DCI Jon Hodgeon, they'll raise their red flags to highlight the things you can watch out for - so you'll know whether the police officer you're talking to is a criminal in disguise.

PRESENTER: SHARI VAHL

PRODUCER: TOM MOSELEY