Josh Clarke, 22, of Portland Road, is accused of killing Mr Collins, 36, outside the Aldi supermarket in Bath Street in the town on June 6, 2008.

Clarke denies murder but admits manslaughter, the court was told this week.

A jury was sworn in at Nottingham Crown Court on Tuesday and heard medical evidence from pathologist Dr Elizabeth Turk.

It is alleged Mr Collins, a production planning manager from Ilkeston was kicked and punched.

Paul Mann, prosecuting, said Mr Collins, known as Merv, was attacked by Clarke, "who launched at him with a series of punches and kicks", after an argument that had started outside a takeaway on Bath Street
continued as the pair made their way home in the same direction towards
Cotmanhay.

He said of the attack: "Merv just tried to cover his head with his hands. After that the defendant moved away.

"Merv unfortunately gave the defendant just the excuse he was looking
for – he issued an empty threat, saying, 'Do you want some more?'

"And then he gave him some."

Earlier Mr Collins, of Newstead Road South, who worked in Nottingham, had been chatting to Clarke's friend Charlotte Hill, who accused him of following them.

Mr Collins then called her and she slapped him across the face, the court heard.

Defending Clarke, Orlando Pownall said that he only kicked him to the head once and there was no evidence to suggest he was kicking him while he was on the ground.

Dr Turk said: "The overall injury pattern, taking into account the injury to his brain and neck, definitely suggests there was more than one impact."

However, she could not say for certain whether the impacts were from kicks or punches or from striking the ground or walls near to where Collins died.

The trial continues.