Scammers posing as council staff are trying to extort money out of unsuspecting victims in north-west London.

Harrow Council urged residents to be “extra vigilant” following reports of rogue roofers offering to carry out unnecessary repairs in the borough.

In one instance, an imposter wanted £6,000 from a Harrow resident to carry out a series of dubious household repairs.

He was found out before getting his hands on the cash, but the another resident was conned out of a “substantial” amount after being convinced their house needed major roof works.

Simon Legg, service manager at Brent and Harrow Trading Standards, said: “Unfortunately, not everyone who comes to the front door is genuine.

“It is important to be aware that some people are willing to prey on the trusting nature of our residents and it is everyone’s responsibility to challenge unannounced visits and suspicious activity.

“Most legitimate businesses do not have to use door to door sales techniques to attract custom – don’t let these people into your home and certainly do not pay them cash.”

The council added that people should always ask to see identification and write down their name and number.

It explained that while council officers do occasionally carry out unannounced inspections, they always carry ID and are happy to wait for their identity to be verified.

Officers will never ask people to pay cash for on the spot inspections or repairs, it added.

Mr Legg urged people to contact Citizens’ Advice on 03454 040506 if they feel they have been targeted by bogus tradespeople.