A gay man accused of killing his ex-boyfriend by pouring petrol over his head and setting him alight was seen with a scar on his neck the following day, a court has heard.

Nadim Kurrimbukus, 25, also known as Adam, is said to have callously torched 23-year-old Charlie Davies outside his home in Templedene Avenue, Staines, on June 14 last year.

His friend Nigel Forbes-Jones said he noticed the mark on Kurrimbukus's neck the next day when they met to talk about the attack.

Kurrimbukus, 25, of Heath Road, Hounslow, and his friend Yusuf Dulloo, 27, of Ashton Gardens, Hounslow, are on trial at Kingston Crown Court where they deny murder and arson.

Mr Forbes-Jones, told the jury that "it could have been maybe a burn, sort of a scald mark," but he admitted in cross-examination that it could also have been a rash or caused by scratching, and that a photo taken of Kurrimbukus on June 18 did not show a scar.

The court heard earlier that a man who was seen running away from Mr Davies after he was set on fire at about 11.15pm was wearing a hood and sunglasses, and had covered his face.

Mr Forbes-Jones, who first met Mr Davies in gay bar West 5 in Ealing, said the supermarket worker had started a sexual relationship with a colleague at Tesco in Syon Lane, Osterley, after he broke up with Kurrimbukus at the end of 2007.

He said: "I believe it was Charlie who told Adam (about the relationship). He did say that he did not feel that Adam would like the fact that he was seeing someone else."

He added: "Charlie felt that Adam was in control of his life and that is one reason why the relationship ended."

Victor Temple QC, prosecuting, earlier told the jury that Kurrimbukus "decided to maim and disfigure" his former boyfriend because "if he was not going to have Charlie Davies, nobody else was going to have Charlie Davies."

Mr Davies died in hospital 12 days after the attack from horrific burns to 75 per cent of his body.

PC Katy Hanlon, who was one of the first police officers to arrive in Templedene Avenue, broke down in court as she described how she found Mr Davies lying severely wounded in his neighbour's garden.

She needed counselling for post-traumatic stress disorder after witnessing the aftermath of the attack, the court heard.

Fighting back tears, she said: "He mentioned he couldn't get his key in the door and that he thought they had done something to it.

"Mr Davies said in the ambulance that they had poured white spirit over him.

"He said they came from behind me wearing balaclavas with the hood up."

Kay Davies, Charlie's mother, told the jury that she initially believed it was a homophobic attack. He had been hit over the head with a bat in a previous assault in March, she said.

But she later told police that she was convinced she heard Kurrimbukus' voice say: "Do you think they are scared now?" from a nearby alleyway moments after her son was set on fire.

She said: "I find it very hard that the voice was Adam's. I was very fond of Adam, I thought he was part of my family and I find it very hard to think that Adam could be involved at all."

The trial continues.