POLICE investigating a serious collision involving a motorcycle in Kent say they want to speak to a couple who stopped at the scene.

The crash happened in Harley Bottom Road, Longfield, near Dartford, at around 11.30pm on Sunday.

The rider of the motorcycle, a 29-year-old from New Ash Green, near Gravesend, and the passenger, a 33-year-old man from Orpington, are still in hospital. The passenger is in a critical condition.

Police say the man and woman they want to speak to were travelling along Hartley Bottom Road towards New Barn. The man identified himself as "Dave", but police have no further details.

The crash has been referred to the Independent Police Complaints Commission because a police car was near the scene when the incident happened.

Anyone with information is asked to contact police on 01622 798538 or 01622 798535.