The M1 is closed southbound after a collision believed to be caused by a lorry driver suffering a medical episode.

Emergency services were called to carriageway between J11 for Luton and J9 Redbourn after reports of a lorry in collision with a vehicle, then striking the central reservation.

The driver has been taken to hospital.

A full closure is in place and motorists are asked to avoid the area.

Highways England say 500 litres of diesel has been spilled.