Police have warned local people to be wary of cold callers after at least two Harrow residents were targeted in a suspected scam.
The householders were contacted by callers claiming to be from a security firm working with the police or part of a government scheme to protect homes.
They used the company name SSH Fire and Security Limited and gave a phone number – 0845 413 3775 – which does not exist.
Police said the tricksters may well be using the name of a legitimate company that is not involved in their scam.
But stressed there were no such police or government-backed security initiatives currently running in the Harrow area.
They warned residents not to provide any personal details if they are contacted in this way and to inform them immediately by calling 101.