Police are asking for witnesses to come forward following the collision in Chalk Hill yesterday.

The incident occurred near the junction with Pinner Road shortly before 11.30am on Wednesday, June 3, and for reasons unknown at this stage, a grey Suzuki Alto was in collision with a pedestrian, a man aged in his 80s.

The man suffered a head injury and was taken to Watford General Hospital to receive further treatment, where he remains in a stable condition.

The driver was not injured.

It is believed there were a number of people in the area at the time and police are appealing for anyone with information about the collision, or events prior to it, to contact them.

Anyone with information is asked to contact police via the non-emergency number 101, quoting ISR 226 of June 3.