A call for witnesses is being made after an aggravated burglary saw two men posing as police steal cash from a woman's home in Pinner .
PC Darren Wiltsher of Harrow Met told getwestlondon: "They were not in uniform but just said they were police - and took advantage of the victim.
"They were holding a screwdriver and a knife."
The victim believed the men were a relative returning home, police were told.
Anybody who may have witnessed the incident is to call crime stoppers on 08000 555 111 or 101.
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