AN Air ambulance has landed on the M40 to take away an injured motorcyclist after a crash on the junction 1a slip road.

The man, in his 60s, suffered multiple 'life-threatening' injuries and has been taken to Wexham Park Hospital, Slough, air ambulance spokesman Michelle Hewitt said.

The accident, which happened at about 1.20pm, had caused a complete standstill with cars gridlocked as paramedics treated the man on the side of the road.

Traffic is now moving again but only a single lane is open.

Highways Agency officers and Police attended the scene.