A Two-pronged investigation has been launched into a road smash involving an ambulance which was taking a patient to hospital.

The patient, a 61-year-old terminally ill cancer sufferer, was being rushed under a blue light to the University Hospital of North Tees, Stockton, following a deterioration in his condition.

Already critically ill, the man suffered a heart attack in the ambulance, but it is not clear whether that was before, or as a result of the collision with a car on a traffic light controlled junction at Stockton.

The ambulance had been travelling along Oxbridge Avenue and had reached the junction with Bishopton Road West and Bishopton Avenue, when the collision occurred.

A spokesman for the Tees East and North Yorkshire Ambulance Service said: "It is the subject of a police investigation and we are conducting our own investigation.

"We don't know the circumstances.

"We were carrying a gentlemen aged 61, who was described as seriously ill, to the North Tees.''

The spokesman said two ambulances were immediately sent to the scene, one taking the dead patient and a crew member from the ambulance involved in the smash, to the University Hospital of North Tees for a check up. The second ambulance took the second crew member, who was suffering minor injuries, to the same hospital.

The 19-year-old Stockton driver of the Vauxhall Astra - the car involved in the smash - was uninjured.

A spokeswoman for Cleveland Police said: " At approximately 9.40 hours on the morning of April 28, an ambulance was travelling north along Oxbridge Avenue, Stockton.

"Whilst passing through the junction of Bishopton Road West and Bishopton Avenue, the ambulance collided with a Vauxhall Astra. Both vehicles came to a halt in the middle of the junction.''

Cleveland Police are appealing for witnesses to the accident to come forward. Anyone with information should speak to PC Craig Portas of the Crash Investigation Unit on (01642) 301552.