Beryl Lawson, 82, of Powfoot, says she initially thought she was helping police snare a criminal working in an Annan bank.
Recalling ‘panic stations’ after a phone call last Thursday morning, Beryl said: “When someone says they’re from a police fraud department, you take it as true.”
The grandmother was told £450 had been taken from her bank account.
And she said: “I was asked if I could possibly get into the bank within ten minutes, take out some money, and put into their safe account.
“They said they were suspicious of someone in Annan bank, and there would be surveillance.”
Beryl was told there would be surveillance both inside and outside the Royal Bank of Scotland in Annan High Street, but arrived to find it closed.
She phoned the fraudster, who instead directed her to a Lockerbie branch where she transferred £3330.
And she said: “It was the speed I was pushed into it, you know?”
She added: “I really thought I was helping, and I was doing my duty to the police.”
Beryl was faced with repeated calls to her mobile phone asking about her progress, having been told she would receive a reward.
And she said: “I felt like I had a gun to my back.”
She was then directed to transfer a further £8000 sum from Santander in Dumfries, but this was blocked thanks to a £2000 limit.
Mrs Lawson went to Loreburn Police Station in Dumfries who flagged up the entire situation as an elaborate scam.
In a second case, a man in Annan has also fallen victim to a telephone scam, losing £236.
PC Iain Leggett of Annan Police Station said: “A person living in Carlisle Road received a telephone call from someone claiming to be from Microsoft.
“They got onto his computer.”
Police Scotland note that they will never ask anyone to transfer money to a separate account, and warn the public never to allow anyone remote access to their computer.