Detectives are keen to trace a motorcyclist who chased a car after it knocked down an 85-year-old man in Saltaire.

The biker is believed to have tried to follow the T-registration Mazda after it sped away carrying Harry Atherton on its bonnet for 50 yards.

And police are also seeking a second witness who was travelling behind the Mazda just before the incident.

The male driver was in a pick-up truck and is believed to have spoken to a police officer before leaving the scene.

Mr Atherton, of Park Street, Saltaire, was critically ill in Bradford Royal Infirmary last night.

He was hit near the junction of Maddocks Street in Saltaire on Friday at about 3pm.

Until paramedics arrived on the scene, Mr Atherton was given first aid by firefighters from Shipley.

The car, which is believed to have been stolen from the Shell garage in Bingley Road, Saltaire, was dumped near the Royal Hotel in Crag Road, Windhill, minutes after the incident.

Detectives are keen to pinpoint the exact movements of the car throughout the incident.

Detective Chief Inspector Roger Gasson of Keighley police who is leading the investigation said: "It is important that we get as much information as possible about the movements of this car, from when it was stolen to the time it was abandoned.

"The hit-and-run happened only minutes after the car was stolen. We believe a motorcyclist chased the car, but eventually had to give up in the Owlet Road area of Windhill.

"Shortly afterwards the car was dumped and the driver ran off in the direction of Stubbing Way.

"The driver drove through Shipley with the windscreen smashed. He was seen by a lot of people."

Chief Insp Gasson said the car was now under scrutiny by forensic science officers.

Mr Atherton was knocked down close to Fanny's Ale and Cider House and the junction with Maddocks Street.

A witness said the pensioner was carried on the bonnet for about 50 yards and then flung off when the car braked sharply.

An 18-year-old man who was arrested in connection with the incident has been released on police bail pending further enquiries.

Anyone with information should ring Keighley police on (01535) 617080.

Pictured with the Mazda involved in the incident is Detective Inspector Angela Williams.