POLICE are searching for four witnesses after a motorcyclist was left fighting for his life after a serious crash.

The man in his 20s was found with head injuries following the smash in Greenstead Road, Colchester, in the early hours of Saturday.

Essex Police were called by their colleagues in the East of England Ambulance Service at 4.10am.

The man's bike had collided with a metal sign post.

He was taken to hospital for treatment and suffered life-threatening injuries.

The incident happened close to the junction of Hythe Station Road.

Expert officers from the Serious Collision Investigation Unit want to speak with a man, believed to be a taxi driver, and three women who were seen near the site of the collision.

The man was driving a grey, possibly private hire taxi, and was described as black, with short cropped hair and a moustache.

He spoke to ambulance staff with what was believed to be a foreign accent, and is thought to be between 35 and 45 years old.

There are no descriptions of the three women, but they stopped to help in the aftermath of the crash.

All four people stayed at the scene for a short time after the collision before leaving, and are being treated as witnesses.

A spokesman for Essex Police urged anyone who knows who the people are to come forward as soon as possible.

He said: "If this is you, or you know who these people are, please contact the Serious Collision Investigation Unit as soon as possible on 01245 240590 or email collisionappeal@essex.pnn.police.uk

"The man’s family have been told of his injuries and our officers will be supporting them.

"Enquiries continue."