Police are investigating after a driver who had a stroke on the motorway was allegedly assaulted by a passing motorcyclist.

Officers said the incident allegedly occurred at around 10.15am between Staines and Heathrow Airport on the M25 on November 24. 

Police were called to reports of a suspected drink driver hitting other cars before stopping on the hard shoulder.

A number of drivers pulled over to find out what had happened and it soon became apparent that the driver had in fact suffered a stroke 

Before emergency services were on scene, a motorcyclist pulled over and assaulted the driver before leaving.

The victim, a man in his 40s, is in hospital receiving treatment.

If you saw anything, contact Surrey Police on 101, with the reference P18281601.