Image caption The police officer was taking part in a speed check operation when he was hit by the car

A Metropolitan Police traffic officer who was hurt in a hit-and-run incident in south London has died.

PC Andrew Duncan, 47, was on foot when he tried to stop a car in Sutton at 00:50 BST on Friday but the vehicle struck him.

The father-of-two died in hospital in the early hours, the Met said.

A 25-year-old man arrested on suspicion of causing serious injury while dangerous driving has now been arrested on suspicion of murder.

Police said a woman was arrested late on Saturday on suspicion of perverting the course of justice. She remains in custody at a south London police station.

The incident, which involved a Volkswagen Golf, happened on Reigate Avenue with the junction of Rose Hill.

The vehicle was later found abandoned nearby.

PC Duncan and a police colleague were carrying out speed checks in the area at the time.

'Courageous policeman'

Metropolitan Police Commissioner Sir Bernard Hogan-Howe, said: "On behalf of the Metropolitan Police family, I would like to offer my sincere condolences to his wife and children, parents, family and friends.

"Andy was a hard working and courageous policeman. He served the community as both a police officer and as a scouting volunteer.

"The night he was injured, he was doing a job that he loved and we all had every right to expect he would return safely to his home and family - tragically that was not the case."

PC Duncan was married and had a son and a daughter.

His death is a tragedy and a reminder of the courage and sacrifice shown daily by the men and women who keep London safe Boris Johnson, Mayor of London

He joined the Met in 1990 and worked in Battersea, Hammersmith and Fulham, before joining the South-West Traffic Unit in 2004.

London Mayor Boris Johnson said: "His death is a tragedy and a reminder of the courage and sacrifice shown daily by the men and women who keep London safe.

"My thoughts and those of every Londoner are with Andrew's wife and children at this time."

According to the Police Roll of Honour Trust website, the last Met officer to die as a result of crime while on duty was PC Gary Andrew Toms in April, 2009.

He was fatally injured attempting to arrest suspects in a vehicle in east London.

Before that, the previous Met officer to die as a result of crime was PC Kulwant Singh Sidhu, who fell through a glass skylight while pursuing suspects in October 1999.