A woman in her 70s who was almost conned into revealing her bank details to a bogus policeman has warned others to be vigilant.

Retired personal assistant Pearl Kosky is the latest victim of the courier fraud scam, after a man impersonating a PC from Holborn Central station tried to trick her into revealing confidential bank information during a telephone call.

The man, posing as PC Denton, told Miss Kosky police had arrested two men with fake copies of her bank card and advised she contact her bank immediately, during the call just after 11pm on December 9.

She described the call as “really authentic” and only narrowly avoided being conned when she noticed there was no automatic menu on the bank’s phone system and dialled 999.

The courier fraud scam works as the con artist does not hang-up after calling the victim. The telephone line remains open and, although the victim believes they are calling their bank, they are still speaking to the con artist.

Many unwittingly reveal bank details or hand their cards over to couriers who visit their homes.

Miss Kosky, who lives in Finchley Road, Swiss Cottage, said: “It’s being performed in a very professional way and I think they’d take a lot of people in and I think a lot of older people may have lost money that night.”

There have been 59 reports of courier fraud in Camden from January to September this year, down from 232 reports in 2012.

Det Serg Steve Chappell said: “I am urging the community of Camden to be extra vigilant if you receive a call from someone claiming to be from your bank.

“If you have any information that can help with this investigation or have been a victim please contact police via 101.”