A man murdered his mother by burning her alive with petrol.

Former offshore worker William Kelly shouted "die, die" as his mother Cathy Kelly was engulfed in flames.

The 42-year-old murdered his mother at their home on Kilmaurs Road in Kilmarnock, East Ayrshire, on February 11.

Ms Kelly had bruising, broken ribs and suffered second degree burns to 45% of her body. She also had a cut to her tongue and bruised lips.

He violently punched and kicked his mother leaving her lying face-down on the living room floor.

The High Court in Glasgow heard Kelly broke off from the assault to take a phone call, which he answered claiming to be a worker in an Indian restaurant.

After finishing the call, Kelly went back and further assaulted his defenceless mother, who referred to him as "ma boy".

Judge Lady Stacey deferred sentence on Kelly until January 10 to obtain background reports.

She told the jurors: "What you have had to listen to has been distressing and sad."

The court heard Kelly was angry because his mother had embarrassed him at a 21st birthday party by drinking too much.

He ordered his mother and his then partner Eleanor Banks to leave and called a taxi.

When they returned home around 11pm he dragged his mother by the arms into the house after she fell as she got out the taxi.

Mrs Banks, 44, told prosecutor Ashley Edwards QC: "William was emptying a petrol can on to his mum - all over her - and I couldn't stop him.

"I was standing screaming 'You're going to kill your mum' and he was saying 'die'. The liquid smelled like petrol.

"He went down and he set fire at the bottom of her legs. She just went up like an inferno. I've never seen anything like it. In the blink of an eye she was on fire."

Forensic scientists revealed the top Cathy was wearing that night was saturated in petrol.

His mother was recovering from a brain haemorrhage she suffered in December 2016, which it was alleged was caused by beatings inflicted by Kelly.

Kelly even boasted in a text sent in early December 2016 of wanting to give his mother "two black eyes for Christmas".

When he was in Glasgow Royal Infirmary being treated for burns he confessed to a nurse who was treating him, saying: "I did what I had to do. I was provoked. She got what she deserved."

Following the blaze, Kelly's only concern was the safety of his West Highland terrier Poppy.

After deliberating for 90 minutes, the jury unanimously convicted Kelly of murdering his mother.

Kelly is now facing a life sentence and showed no emotion as he was led away to the cells.