An 80-year-old widow was conned out of £16,000 and almost remortgaged her home after falling for an e-mail scam.
Police are urging people to delete any e-mails that seem suspicious
The pensioner, from Bridgend, believed she would inherit $30m (£14.6m) after receiving an e-mail saying she was the only relative of a dead businessman.
It said the wealthy German and his wife had died in a Concorde crash in 2000, about which she was later sent faked BBC News website reports.
Detectives from South Wales Police are investigating the scam.
Pc Steve Carpenter was contacted by the woman's daughter when she learned about the scam.
He said the email said she had inherited $30m from a relative, who was a wealthy German businessman, who was killed with his wife in a Concorde crash in 2000.
The e-mail said the crash in which the woman's "relative" had died had happened in Monchengladbach, Germany.
But the actual Concorde crash in 2000, in which 113 people died, happened in Paris.
The pensioner had been drawn into a dialogue with the scammers, resulting in around 300 e-mails.
Pc Carpenter said she wanted to remain anonymous.
He said: "She's 80 years old but was quite internet-aware, aware of junk mail but this one was quite well written, well presented and got her attention."
Over a month, the woman, who lives in Brackla in Bridgend, was told she had been traced as the only relative of the dead couple who had left her $30m in their will, said Pc Carpenter.
He said: "She sent various amounts totalling £16,000. The thing is she's drawn the money out willingly from her own bank so from the bank's point of view there is not a lot they can do."
After she had paid the scammers £16,000, she was told £10,000 more was required but the widow said she did not have the money.
Date of birth
Pc Carpenter said: "They asked her could she remortgage her house. She said 'I need to tell my daughter' and they said 'Don't tell your daughter, keep it quiet'."
However, the woman did tell her daughter who then contacted the police.
"You get a sick feeling in your stomach and loathing of these people" said Pc Carpenter.
"I believe they did know her age as she had to pass on her date of birth and details to carry on the deception."
Pc Carpenter urged people not to fall for similar scams and said: "My advice is if in doubt, leave it out. If you suspect anything, don't open it, delete it.
"If it's suspect, it's suspect. If there's any element of doubt, if it seems too good to be true, it usually is."
Anyone who receives a scam e-mail should contact their local police station.