A man has admitted attempting to murder a soldier in Edinburgh after holding him hostage in a flat when he discovered him lying in bed with his sister, a court has heard.

Dylan Rigby, 20, pleaded guilty on Thursday to attacking 18-year-old Cobhan McLelland with scissors, knives and boiling water in a two-hour ordeal at a flat in Kidlaw Close in the Gracemount area of the city in March.

Rigby flew into a rage after discovering McLelland in bed with his sister after returning from a night out at around 6am on Saturday March 22, prosecutor Stephanie Ross told the High Court in Edinburgh.

Rigby threw McLelland to the ground, and repeatedly stamped on and kicked him, before attacking him with a bottle, scissors and a knife and then pouring boiling water over him, she told the court.

Ms Ross said Rigby’s sister Rebecca was “shouting but he did not stop. As she left she heard the door being locked behind her and she phoned the police”.

Heavy-set Rigby, wearing a black polo shirt and jeans in the dock, nodded and smiled at two family members who were sitting in the public gallery in court.

At one point, Rigby put a knife to the squaddie’s back and scissors in his mouth, threatening to cut off his tongue, as well as terrorising him by making threats to rape and kill him, the prosecutor added.

She said: “Mr McLelland was crying, begging for his life. The accused was saying ‘don’t f*** with me, do you know who I am?’

“Throughout the assault the accused was saying he was going to kill the complainer and said he could rape him if he wanted to.

“The accused was laughing and dancing.

“At one point he took him to the window with a knife at his back and put the scissor blades over his tongue, threatening to cut off his tongue.”

A large police presence stormed the flat and Rigby was arrested by armed officers at around 8.22am, the court heard.

Mr McLelland was rushed to hospital with a fractured nose and wrist, and a deep cut to his forehead, as well as cuts and burns to his shoulder, arm and back, before being discharged around a week later.

He was treated at a specialist burns unit after the scalding water burned patches of his skin, and was also helped by psychiatric teams after suffering from flashbacks and nightmares, Ms Ross told the court.

The charge states the attack was to Mr McLelland’s “severe injury, permanent disfigurement and danger of his life” and that Rigby “did attempt to murder him”.

Rigby was remanded in custody for a criminal justice social work report to be prepared before sentencing as he is not yet 21.

He will next appear in court on October 28 at 9.30am, said judge Lady Carmichael.