Jurors listened to a highly charged and emotional 999 call in which a friend of murder victim Chris West was describing the scene in the Monkfield Arms pub on October 27.

Gregory Baillie told Cambridge Crown Court he was a school friend of Mr West and, on the night of the Halloween party at the pub, he had been playing pool with Daniel Berryman who was stabbed by a "man in a hat".

He talked about a "man in a hat" who he said was sitting in the bay window of the pub in the moments before Mr Berryman was injured.

He said: "Dan was about to take a shot and the man in the hat bumped into him - a deliberate bump, with shoulders."

He told the court, "the man in the hat" walked away and then returned as Mr Berryman was leaning over the pool table.

"The man in the hat returned and there was a swinging motion over his right shoulder and he hit him [Berryman] in the chest.

"He [Berryman] stood up and he looked at me with a blank expression and walked towards me and lifted up his shirt to reveal the wound. The guy in the hat walked off towards the exit."

Mr Baillie told the court he never saw a weapon, but when he saw the wound it was "obvious it wasn't a punch as the blood was pumping out".

"It was clear it was a stab wound and a matter of life and death in my eyes so I phoned 999," he told the court.

The 13-minute 999 call was made at 12.32am and Mr Baillie was given advice on how to stop the wound from bleeding by applying pressure. He can be heard telling the operator Mr Berryman was receiving treatment from a doctor but a few minutes in, he told the operator he had walked outside and there were now two men lying on the ground.

In a harrowing account, the jury heard him describe to the 999 operator how Mr West was being resuscitated and another man was lying next to him and had been handcuffed.

He can also be heard asking "who is he?" as he attempts to find out who the man in the hat is. He becomes increasingly agitated as he believes three people have been stabbed.

During cross examination, Mr Baillie admitted his version of events didn't match up to some mobile phone footage taken in the pub that night.

He is seen talking to another man in the pub while Mr Berryman is showing people his injury.

Isabella Forshall QC, for the defence, suggested that rather than immediately make the 999 call, Mr Baillie engaged in conversation with a male in the pub. Mobile phone footage showed a male, which Mrs Forshall said was Mr Baillie, talking to a male in the pub while Mr Berryman was seen showing people his injuries.

Mr Baillie told the court he recalled guiding Mr Berryman to friends and going outside to make the 999 call.

Kai Nazir denies murdering Chris West and also faces charges of attempted murder and grievous bodily harm with intent in relation to Mr Berryman and a fourth charge of carrying a bladed article.

The case continues.