A Metropolitan Police officer who was arrested on suspicion of manslaughter after the death of a woman in west London has been released on bail.
The 34-year-old officer, who works in central operations, was off duty at the time of the alleged offence.
The 64-year-old woman died following an altercation, understood to have involved motorists, in Hillingdon on Tuesday.
The Met said it has informed the Directorate of Professional Standards.
The Independent Police Complaints Commission has also been made aware.
A post-mortem examination on the woman is due to take place later on Thursday.
Her next of kin have been informed of her death.
The officer was arrested at his work place and taken to a south London police station on Wednesday.
A spokesman for Scotland Yard spokesman said the altercation happened in Snowden Avenue at approximately 1630 GMT and the woman had been pronounced dead at the scene.
He added: "[The man] has now been bailed to return in mid-December pending further inquiries."
Police have asked for anyone who was in the area at the time to contact them on 020 8247 7821 or to call Crimestoppers on 0800 555 111.