Four scam attempts have been thwarted by police and vigilant residents across Suffolk in the last two days.
On Monday a woman from Brandon withdrew cash from her account after someone called claiming to be from the Metropolitan Police claiming someone had tampered with her account.
The caller said a courier would be sent to pick up the money and a taxi arrived soon after.
But after a short conversation with the driver, the woman became suspicious and sent away the taxi without handing over the cash.
The taxi appeared to be from a local firm but when spoken to the company confirmed they had not sent a vehicle.
The driver is described as white, of stocky build, in his late 20s - early 30s, with very short brown hair, clean shaved with a European accent.
He was wearing trainers, jeans and a dark coloured jacket, possibly a tracksuit top.
On the same day an elderly woman in Ipswich was called by someone claiming to be from Hammersmith Police in London saying money had been stolen from her bank account and she needed to contact her bank.
She called Suffolk police who called the Metropolitan police who then confirmed it as a scam.
Yesterday an elderly man from Brandon was called by someone claiming to be from Hammersmith Police who said money had been taken from his bank account.
He contacted Suffolk police who confirmed it was a scam.
The same day a woman in her seventies withdrew money from her bank after being called by someone claiming to be from the police.
She was told to take the money home and someone would be sent to collect it.
Again, police were contacted and the woman was informed it was scam.
Police believe the incidents may all be linked.
Community Safety Manager Alan Osborne said: “It is pleasing that we have had four potential victims of this scam but that on each occasion money has not been sent either due to the action of the resident or intervention by others.
“The offenders are clearly targeting elderly, vulnerable people and therefore it is important that we continue to spread the word and raise awareness of this type of crime.
“If you know someone then please tell them about this scam and the importance, no matter how convincing the person is, not to give out bank details or agree to withdraw any money and pass it to a courier or taxi driver.”
Police are warning people that your bank or police will never ask for bank details and would never call and ask you to withdraw money.
If you receive such a call, leave the landline for at least five minutes to make an outside call as fraudsters will keep the line open and play ringtones or hold music so the victim believes they are making a call to a legitimate number.
If you have been a victim call police on 101 or 999 if you are vulnerable and need police assistance.
Remember to allow your landline to clear for at least five minutes before you call or ideally use an alternative line.