Witnesses urged to come forward following Doncaster collision

Witnesses to a collision in the Thorne area of Doncaster last night are being asked to call police with any information. 
At around 7.30pm, a blue BMW was travelling along Field Road, heading towards Thorne, when it has been involved in a collision with a pedestrian, who is thought to have fallen in the road. 
The collision happened close to the junction with St Nicholson Road. 
The pedestrian, a 60-year-old man, was taken to hospital with suspected minor injuries. His condition has since deteriorated and is now described as life-threatening. 
A 60-year-old man driving the BMW was not injured. 
Officers want to hear from anyone who saw what happened and particularly anyone who may have dash-cam footage of the incident, or of the pedestrian or car before the collision. 
If you can help, please call 101 quoting incident number 955 of 20 January 2018.