The Metropolitan Police has issued a new picture of PC Andrew Duncan, who died following a suspected hit-and-run collision in Sutton.
A further two men have been arrested in connection with the crash, after another was remanded in custody accused of causing death by dangerous driving.
More top news
A man with no recollection of who he is has been found in London, with police appealing for help to identify him.
London Underground has made a new offer to unions to try and avert next week's tube strike. But will it work? Here's what you need to know
The Metropolitan Police has responded to allegations that they refused to enter the water to rescue a teenager who was drowning