Police have warned the public to be alert to scammers after an 89-year-old woman was conned out of £100,000.
Posing as bank officials and police, the fraudsters told the victim from Atherstone, Warwickshire, that there was a problem with her bank account.
They then persuaded her to transfer £100,000 from her account to a different account "to be safe".
Detective Chief Inspector Sean Paley said: "While people are generally aware of such scams, these criminals target vulnerable members of the community.
"I would urge people to talk to close friends and relatives who they think could be at risk."
Officers have said people should be on the alert to similar scams being carried out elsewhere in the country.
Anyone who suspects they have been targeted should call police on 101.
For further information, call Crimestoppers on 0800 555 111, or visit www.crimestoppers-uk.org or www.actionfraud.police.uk