A non-police firearm has been recovered from the scene of a fatal shooting of a man at a petrol station in east London, the police watchdog has revealed.
Armed officers attended an Esso petrol station in Collier Row Road, Romford, after the man called police at 3.50am making threats and claiming he had a firearm.
He was shot at around 4.45am and was pronounced dead at the scene about half an hour later.
Forensics officers moved a tent into the petrol station on Monday morning as much of the road remained cordoned off.
The incident was referred to the Independent Office for Police Conduct.
A spokesman said: "Three firearms officers attended and located the man at a petrol station near to the address and he was subsequently shot.
"What appears to be a non-police issue firearm was recovered from the scene and this will be examined by experts."
IOPC regional director Sarah Green said: "As we begin our investigation, my thoughts are with the man's family and friends and all those affected by this incident.
"Our investigators are at the scene carefully overseeing the collection of forensic evidence. We have attended the MPS (Metropolitan Police Service) post-incident procedures where officers are providing us with witness accounts.
"The three officers were equipped with body-worn video, which has been provided to us, and we are also recovering CCTV from the area, as well as undertaking house-to-house inquiries.
"We have met with the man's next of kin and we will be keeping them informed as our investigation progresses."
Linda Leonce, 45, who lives in nearby Lodge Lane, said: "I was woken by a few kind of 'pop, pop' sounds and then there were some sirens."
Fireman Darren Buckley, 50, who lives on the road, said: "I didn't hear gunshots, but seeing all the vehicles I thought it was a car crash or something, seeing all the blue lights.
"There was just so much commotion going on outside. It was all kicking off. One of the police cars left sharpish with its sirens on just after 5am."
Romford's Conservative MP Andrew Rosindell tweeted: "Shocking incident in Collier Row today, just relieved no member of the public has been harmed. Thank you to the Police for protecting our community."