Doug Varey was offered security software which sounded like a good deal.
It turned out to be a frightening scam that cost him thousands of pounds. He was shown images which appeared to be of Russian gangsters buying weapons with his money, and handed over thousands of pounds to make it stop.
Indian police have now raided call centres thought to be involved.
Rory Cellan-Jones reports.
Camera: Rachel Price. Edited by Peter Page