POLICE today closed the M40 southbound following a fatal crash.

The motorway was closed between junctions four and 1A.

Police said traffic was being diverted on to the A40 but there were extensive tailbacks and motorists are being advised to avoid the area for the foreseeable future.

Seven vehicles were involved in the crash and one person has died, several people have been injured and have been taken to Wexham Park Hospital.

A man has been arrested at the scene and is in police custody.

Police are asking anyone who may have witnessed the incident to contact Sgt Steve Madoc-Jones at Amersham police station via 0845 8 505 505, or if you do not want to talk to the police or give your name, call the Crimestoppers charity on 0800 555 111.