The trial of a man accused of two infamous double murders in Pembrokeshire has restarted in front of a new jury.

The trial of John William Cooper, accused of killing brother and sister Richard and Helen Thomas and tourists Peter and Gwenda Dixon, was suddenly stopped on Monday morning after an issue was raised with the judge.

The judge, Mr Justice John Griffith Williams, discharged the jury and a new jury was sworn in on Tuesday morning. The trial has restarted from the beginning.

Cooper, aged 66, of Spring Gardens, Letterston, denies killing farmer Richard Thomas, aged 58, and his sister Helen, aged 56, at their home at Scoveston Park on December 22, 1985.

Cooper also denies the murder of Oxfordshire holidaymakers Peter and Gwenda Dixon, aged 51 and 52, in June, 1989.

He has also pleaded not guilty to raping a 16 year old-girl, indecently assaulting another and trying to rob money from a group of five youngsters, near the Mount Estate, Milford Haven, all on March 6, 1996.

Gerard Elias, QC, opening the case for the prosecution, told the court further chilling details of the murders at Scoveston Park.

Mr Thomas was shot in the head as he tried to escape his ‘merciless’ executioner, he said.

Mr Thomas, a millionaire, arrived home late on December 22, 1985, as farm labourer John William Cooper was in the process of robbing his sister Helen, it was alleged.

Forensic examination of the scene showed that it appeared Mr Thomas had been hit in the head by a ‘raking’ shot from a 12 bore shotgun, probably as he tried to run away.

He took refuge in an outhouse, but Cooper allegedly cornered him and killed him with a shot to the abdomen, which was fired when the muzzle of the gun was actually touching his body.

Then a blanket was used to wrap the body and drag it into the house, Mr Elias told Swansea crown court.

Mr Thomas’ body was found on the landing inside the burned down house.

Detectives found a pool of blood in the outhouse, as well as lead cartridge pellets and wadding.

And the driver’s side door of Mr Thomas’ car was still open when police arrived.

Mr Elias said Miss Thomas, aged 56, may have been tied up and left on a bed upstairs in the house, and she had been gagged or blindfolded with a man’s shirt. After the fire had taken hold her body fell through to the ground floor below.

“The prosecution say the need to kill the Thomases no doubt arose because the intruder was afraid that whether by voice or action or appearance he might be recognised or known,” added Mr Elias.

“The defendant had worked for Richard Thomas.”

He described their killer as cold and calculating.

The trial continues.