A teenager who was high on cocaine drove the wrong way down a motorway and killed two Thornton Heath pensioners in a crash, an inquest has heard.

The 18-year-old driver, Christopher Beresford, also died in the smash along with two passengers following a police chase.

James Stafford, 69, and wife Bridget, 70, were travelling home to Thornton Heath along the M4 when their Volvo was hit by a speeding Ford Mondeo driven by Beresford.

Police had chased the Ford Mondeo before it drove on to the wrong lane of the motorway at Newport on September 17, 2007, the city coroner’s court heard.

Mr Beresford, Lee Maggs, 23, and Sam Case, 19, all died in the crash.

The inquest ruled unlawful killing by gross negligence for the deaths of the Staffords, Maggs and Case, while Beresford died from misadventure.

James Burnett was also in the car but survived.

Wayne Maggs, Lee Maggs’s brother, told the court in a statement they had been “driving about” in his brother’s car.

He said: “We had done a lot of drugs, sniffing cocaine, me, Sam and Chris.”

The court heard they were “messing about” in the Penhow area when police arrived.

He was left behind hiding in a garden as the others ran away. The court heard that Wayne Maggs had called a taxi to go home and it was unable to get on to the motorway.

“I had a feeling straight away that it was them,” his statement added.

PC Nathan Price said in a statement that he and a colleague were called to the St Julian’s area of Newport at about 1.50am when a couple reported suspicious activity in their driveway.

They discovered a burgundy Ford Mondeo with the engine still warm. A traffic unit was called to the scene.

About five minutes later they noticed a vehicle travelling “at considerable speed”, followed by the traffic unit’s vehicle.

He said they followed the two cars along the A48 towards the Coldra roundabout and could see a plume of smoke coming from the motorway.

PC Price said they could see there had been “a very serious collision”.

The inquest jury was shown a video of the chase filmed by an in-car recorder, which showed the pursuit reaching the Coldra roundabout, the Mondeo taking the wrong slip road on to the M4 and the traffic vehicle standing down.

In a statement read out on behalf of the Stafford family by their solicitor, Kerstin Scheel, they said: “It is impossible to adequately describe the terrible sense of sadness we feel knowing that our much-loved parents died in such tragic circumstances.

“We believe that there are very important lessons to be learned, lessons that we hope, for our parents’ sake, may save lives in the future.”

An Independent Police Complaints Commission investigation began after the crash.