An ambulance crash which left a man fighting for his life has prompted two investigations.

The ambulance, travelling on an emergency call, collided with a pedestrian in Main Road, Danbury, at 5.20pm on Thursday.

The East Anglian Air Ambulance was called to the scene and the casualty was flown to St George’s Hospital in Tooting in a critical condition.

An alternative ambulance was sent to the original call-out, which was deemed an emergency but not life-threatening – meaning ambulances would be travelling under blue lights.

The ambulance crew was uninjured in the crash, which happened at the mini-roundabout junction with Mayes Lane.

An East of England Ambulance Service spokesman said the trust was co-operating fully with the police investigation, and would also be conducting its own internal investigation into the incident.

He confirmed there was no patient on board the ambulance at the time of the collision.

Essex Police said yesterday the casualty remained in a life-threatening condition.

No-one has been arrested and police enquiries are ongoing.

Anyone who witnessed the crash is asked to contact Stanway Collision Investigation Unit on 101 or email collisionappeal@essex.pnn.police.uk.