A middle-aged man “mercilessly” stabbed his younger girlfriend to death after tying her up on a bed following an argument, a court has heard.

Fuelled by jealousy, Jason Farrell, 49,  attacked 22-year-old  Sammy-Lee Lodwig at his flat then confessed that he had “sliced her up”.

Swansea Crown Court heard that the defendant used to date his victim’s mother and in the days before the attack had been heard expressing a desire to hurt and kill Sammy-Lee, her mother Sarah and Christopher Maher, the man he suspected of being in relationship with Ms Lodwig senior.

Prosecutor Michael Jones told the jury: “He was, in short, jealous.”

Mr Jones read from a “chilling” letter written by Farrell after his arrest in which he wrote: “We went back to my flat and we started arguing.

“Then the next thing I had her tied up and told her I’d had enough and I was going to kill her. I did by repeatedly stabbing her in the face and throat.”

The court was told Farrell,  who denies murder, started a relationship with his victim after she became a regular visitor to his flat for drugs.

Mr Jones said Farrell knocked at a neighbour’s window on April 23, saying:  “I killed her.”

A friend of the neighbour went with six-foot-tall Farrell to his flat in Carlton Terrace in the Mount Pleasant area of Swansea, where he saw the body of Ms Lodwig, who was 5ft 1ins and weighed six stone, on a bed.

Farrell fled after the emergency services were alerted and paramedics found his girlfriend fully-clothed, with cuts across her throat and forehead and “severe bleeding” on the bedding.

It was estimated she died 20 or 30 minutes before they arrived.

A black-handled kitchen knife covered in blood, with the tip of its 15cm blade missing, was found next to the bed.

Forensic scientist Claire Morse said it appeared Ms Lodwig had been assaulted while on the bed.

Mr Jones said knotted and blood-stained dressing gown belts with traces of Ms Lodwig’s saliva were found nearby, suggesting they may have been in or around her mouth.

Injuries to her neck damaged major arteries and veins, while wounds to her chest were deep enough to enter both her lungs.

Cause of death was given as stab wounds to her neck and chest.

The court heard that later that morning Farrell phoned a female friend, calmly telling her, “I’ve killed her. I had enough. She wouldn’t shut up. I sliced her up”, adding that it had been a “slow death”.

Firearms officers tracked him down to an address near his flat that afternoon, where they persuaded him to put down a knife he was holding to his neck before arresting him.

While in custody he said in the presence of officers “that girl didn’t deserve to die like that”, the court heard. He also wrote the letter confessing to the killing.

Mr Jones told the jury: “That letter confessed to murder of Sammy-Lee . He’d actually used the word ‘murdered’. We say it’s a chilling document and one you will be able to see and read for yourself.”

The prosecutor said Farrell was also accused of a “brutal attack” on Mr Maher just days before the alleged murder.

Farrell had split from Sarah Lodwig in 2010 after receiving a 13-year sentence for stabbing another man.

He denies murder, wounding with intent, and unlawful wounding.

But the jury were told he had pleaded guilty to manslaughter, an alternative charge for the killing of Ms Lodwig.

The trial continues.