Jurors trying a policeman accused of murdering Dalian Atkinson have heard claims that 12 factors – including an enlarged heart, end-stage kidney disease and physical exertion – may have contributed to the ex-footballer’s death.

The trial of Pc Benjamin Monk, who denies murder and manslaughter, heard that pain caused by the use of a Taser, the impact of its current, and “psychological disturbance” were other possible factors in the former Aston Villa star’s death.

Giving evidence for a second day at Birmingham Crown Court on Tuesday, forensic pathologist Dr Olaf Biedrzycki said a “key” issue for jurors to determine was whether Atkinson was conscious when he was kicked twice in the head.

The Crown alleges Monk, 42, and 31-year-old Pc Mary Ellen Bettley-Smith, who denies assault, unlawfully attacked Mr Atkinson near his father’s home in Telford, Shropshire, on August 15 2016.

Jurors have heard the 48-year-old, who also played for Ipswich Town and Sheffield Wednesday, went into cardiorespiratory arrest and died in hospital after being brought to the ground by a Taser and then kicked and struck with a baton.

Dr Biedrzycki told the court on Monday that Atkinson was left with two “patterned” footwear marks on his forehead and 15 areas of “under-the-skin” bruising.

Resuming his testimony on Tuesday, Dr Biedrzycki was asked to comment on 12 “potential and possible” contributory factors put to him by Monk’s barrister, Patrick Gibbs QC.

Dr Biedrzycki told the court that Atkinson’s enlarged heart meant he could have passed away in his sleep at any time, or have died “if somebody had looked at him in a funny way in the street”.

The pathologist, who was also asked for his opinions on the impact of the force applied during restraint and handcuffing, told the jury: “I would agree that in addition to the kicks and tasering, the cardinal things are heart and kidney disease.

“This is a case where the key for you guys is to determine whether he was conscious when the kicks were applied.

“If he was conscious then the kicks rendered him unconscious and that was a dangerous situation.

“If he had been knocked unconscious by a Taser-related fall, the kicks … may have prolonged his period of unconsciousness.”

Questioned further by Mr Gibbs, Dr Biedrzycki added: “You can’t know what will happen had the kicks and the Taser not occurred, but I think they are significant factors in the case.”

The trial continues on Wednesday.