A suspected jewel thief died and another was seriously hurt when they were hit by an unmarked police car which had been chasing them.
Two men were arrested after falling off a motorbike
The pair were part of a group of five that police think tried to rob Tiffany & Co in Sloane Square, west London, by driving a 4x4 vehicle into it.
The men were struck by the car after falling off their moped when it hit a parked vehicle in Cadogan Place.
Police arrested three other men on suspicion of burglary offences.
Two were arrested in Cadogan Square after falling off their motorbike, while a third was picked up in a 4x4 car in Acton, west London.
The Independent Police Complaints Commission (IPCC) has been informed about the death and an investigation has been launched.
The break-in took place at about 0135 BST.
Ambulance crews pronounced the man dead at the scene and the injured man is being treated in hospital.
A witness who lives nearby told BBC News: "I heard a tremendous bang and so much noise because the engine of the scooter kept going for quite a while after the accident.
"I went out and the paramedics were over them trying to help them but they looked pretty lifeless."