The Independent Police Complaints Commission is investigating a shooting in north London on Thursday in which a man was killed and a police officer was injured, a statement from the authority said on Thursday night.
An IPPC spokesman said he understood that the dead man had been shot by police at the scene in Ferry Lane, Tottenham Hale at 6:15pm.
"Although it's not known for certain at this stage, we believe the officer was shot first," the spokesman said.
"We do not know the order the shots were fired. We understand that shots were fired by both parties but we haven't got all the details as yet."
Media reports said the injured officer suffered gun shot wounds and was taken to hospital. The officer has subsequently been discharged from hospital.
The Metropolitan Police would not confirm if the dead man had been shot by a police officer.
The incident had been referred to the IPCC by the Metropolitan Police's professional standards department and independent investigators had been sent to the scene.