A BOURNEMOUTH man is reported to be in a "critical" condition after the car he was travelling in overturned on a Hampshire motorway.

The accident on the M3 left the northbound carriageway closed for 12 hours as recovery work and investigations into the cause of the incident took place.

Police have asked for help from the public to pinpoint the cause of the collision, which happened just after 7pm on Friday night.

It is thought that a white Ford Transit van left the road and hit a mile marker post.

The 25-year-old man was taken to Southampton General Hospital by road to be treated for multiple injuries after all emergency services were called to the scene between junctions 7 and 6 at Basingstoke.

Hampshire Constabulary says the man is in a "critical but stable" condition after he suffered a severe leg injury.

South Central Ambulance Service deployed a rapid response vehicle, an ambulance crew, and a Hazardous Area Response Team.

The Thames Valley Air Ambulance was also called to the scene. 

The northbound carriageway was closed for around six hours overnight, and the southbound carriageway was closed for a short period to allow the air ambulance to land.

A spokeswoman from SCAS said crews treated one man at the scene for serious, multiple injuries before he was flown to Southampton General Hospital for further treatment.

Hampshire police thanked the public for their patience while they carried out investigations at the scene of the accident and confirmed the northbound carriageway had reopened this morning.