Officers in cars and a force helicopter were pursuing a Mitsubishi along the A1(M) near Durham at 5.40am yesterday when it crossed the carriageway and hit a Peugeot heading south.

Durham police said a full investigation had begun and the incident had already been referred to the Independent Police Complaints Commission.

The Mitsubishi flew into the air in an attempt to avoid being stopped by traffic officers, a spokesman said.

He said: "The incident happened at around 5.40am on the southbound carriageway near the Bowburn interchange and followed a pursuit by police.

"Officers had earlier been following a Mitsubishi stolen from the Chester-le-Street area which had been spotted on the Aycliffe industrial estate.

"It travelled on to the A167 before turning on to the A1(M) and heading north.

"The Mitsubishi was being followed by trained officers and the police helicopter was also being used to monitor the pursuit.

"Near the Bowburn interchange, a controlled attempt was being made to bring the car to a halt when, in an attempt to avoid this, the Mitsubishi has hit the central reservation and flipped on to the southbound carriageway, hitting an oncoming Peugeot.

"The driver of the Peugeot suffered severe injuries and died at the scene."

The driver of the Mitsubishi, a 23-year-old man from the Chester-le-Street area, later underwent surgery at the University Hospital of north Durham. His condition was not considered life-threatening.

The police hope to interview him over the weekend.

"Officers involved in trying to stop the Mitsubishi were left badly shocked," the police spokesman added.

Some witnesses have already contacted police but they remain keen to hear from anyone with information.

The black Mitsubishi and blue Peugeot were still at the site of the crash near the southbound slip road of the A1M, at junction 61 yesterday afternoon.

Police officers were seen examining the vehicles which lay close together under a motorway sign.

The badly crumpled Mitsubishi 4x4 truck lay on its side with its bonnet open and large clumps of grass wedged into its bodywork. A deep tyre track scarred the slip road next to it.

The small Peugeot 306 was visible only from behind, its windscreen shattered.

Four police cars were later seen being loaded on to tow-trucks, one with a damaged driver's door.

Officers later said they hoped to identify the dead driver and notify family members over the weekend.

The motorway was still closed in both directions at lunchtime yesterday.