The conduct of police officers in the pursuit preceding the fatal collision was investigated by the Independent Police Complaints Commission.

The IPCC report handed to the coroner in December 2007, cleared officers of any wrong-doing.

IPCC Commissioner for Wales Tom Davies said: “At an early stage IPCC investigators found that the police pursuit ended as soon as the red Ford Mondeo entered the motorway in the wrong direction. Indeed, video evidence showed this clearly and we shared this with the families.

“The police driver reversed away from the M4 slip road, and the inquest heard that he did this so that the occupants of the Mondeo could see that they were no longer being pursued.

The commissioner said Mr Beresford could have stopped the mondeo on the motorway hard shoulder, but Mr and Mrs Stafford were not afforded that opportunity.

“Our investigators examined the accident, the events leading to the pursuit and force policies and procedures. We found that officers and control room staff acted properly and in accordance with their training.

After the inquest, Superintendent Nigel Russell, Head of Gwent Police's Road Policing Unit offered his condolences to everyone involved.

He said: "The death of a loved one is a terrible loss in any circumstance. When that loss is the result of an unnecessary collision it seems somehow worse.

"We hope that this tragic event serves as a reminder that driving in a reckless manner can have tragic and fatal consequences.