THE cause of a crash that claimed the lives of devoted couple Graham and Nicola Smith and John Selway will remain a mystery, coroner Richard van Oppen said at the inquest into their deaths.

Families of both Mr and Mrs Smith, who lived in Blackberry Lane, Potterne, and of John Selway, 33, of Steeple Ashton near Trowbridge, attended the inquest in Salisbury on Thursday.

Mr van Oppen recorded verdicts of accidental death on all three victims.

They died in a crash on bends on the A361 Devizes to Trowbridge Road at Foxhangers, near Seend Fork on March 26.

Mr and Mrs Smith died at the scene. Mr Selway, an accountant who was married with a three-year-old daughter, died later in the Royal United Hospital in Bath.

Mr Smith, 42, and his wife, 39, had left their daughter, Lucy, ten, with her grandparents in Devizes.

But their son Sam, 13, accompanied them on a trip to the supermarket in Trowbridge.

They were returning home in their Astra car at 7.30pm when the Vauxhall Vectra driven by Mr Selway crossed the road and crashed into them.

The force of the collision catapulted the Astra through a hedge and into a field.

In a video statement given to police, Sam Smith said: "We were coming round the corner and this car came up like fast round the other way on the wrong side of the road.

"Then it shot in, hit the bank and shot up in the air and barrel rolled and hit us and we rolled into the field."

Mr van Oppen told the families that while there was conclusive evidence that Mr Selway's car was on the wrong side of the road, the police investigation found no evidence that it had struck the verge previously.

In a statement, witness Adrian Slade from Seend said he had been driving out of Devizes down the Caen Hill dual carriageway at about 70mph when he was overtaken by a Vectra travelling at a speed of about 90mph.

Mr Slade said as he went around the bends approaching Seend Fork he saw the Vectra across the road with smoke coming from under the bonnet and from the damage to the car could see there had been a serious accident.

He spoke to the driver who made no response, and because of his concern that the car could catch fire he disconnected its battery.

Mr Slade said he was then aware of a voice calling out and saw a gap in a hedge.

He went into a field and saw a Vauxhall Astra and realised the shouting was coming from the rear.

When he opened the door a boy in the back seat was saying: "I can't get my seat belt off."

He freed him and led him out of the field and his girlfriend, Sally Holdway, took the boy in their car.

Mr Slade said he could not detect any pulse on the man and woman trapped in the front of the Astra.

Andree Chapman of Stonehouse, Gloucestershire, said he was a colleague of Mr Selway at Ringway Parkman, the county council highway contractors, and they had been at a meeting together in Devizes that ended at 7.15pm.

He said: "John was his normal self, cheerful and happy."

He told the inquest he drove behind Mr Selway but stopped for petrol.

He resumed his journey and later came across the crashed Vectra and saw Mr Selway was trapped.

"I said to him you are going to be fine, we will get you out and soon as we can.

"John said: 'Get me out.' He was fully conscious."

The inquest heard that after Mr Selway was freed from the wreckage by firefighters he was airlifted to the Royal United Hospital in Bath but died soon after arrival.

Wiltshire police collision investigator Steve Colwill said both vehicles had sustained frontal crash damage and it was evident the crash had happened on the Devizes-bound side of the road.

He said he could find no evidence of the Vectra striking the verge at any point.

He said it was possible that having crossed to the wrong side of the road Mr Selway might have tried to steer back to his correct side but over-corrected and turned back into the path of the Astra.

PC Colwill said he calculated the speed of the cars immediately before the impact at 51 mph for the Astra and 57mph to 67mph for the Vectra.

Mr van Oppen said: "What we do know is that the Vectra was on the wrong side of the road.

"But we don't know why."