Hundreds of thousands of people fall victim to scams in the UK every year.
Many are run from criminal call centres in India, where teams of fraudsters operate around the clock.
Panorama has obtained hacked CCTV footage from inside one scam call centre that shows exactly how it works.
Reporter Rajini Vaidyanathan tracks down the man behind the crime and the British victims who have been conned.
Spying on the Scammers airs tonight at 8.30pm on BBC 1 and is available on iPlayer
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