A cardiac intensive care specialist has told murder trial jurors it is impossible to state the “exact contribution” of 12 factors linked to the ex-Ipswich Town footballer Dalian Atkinson's death.

Professor Charles Deakin told Birmingham Crown Court the management of the the 48-year-old by paramedics was “suboptimal” and failed to spot possible “early warnings signs” the former striker was seriously unwell.

The Crown alleges West Mercia Police Pc Benjamin Monk murdered the retired striker by kicking him in the head at least twice, intending serious harm.

Monk, 43, has pleaded not guilty to charges of murder and manslaughter, while 31-year-old Pc Mary Ellen Bettley-Smith denies assaulting Mr Atkinson with a baton outside his father’s home in Trench, Telford, in August 2016, after the ex-footballer made threats and smashed a window.

Addressing jurors on Friday after being called as an expert witness by Monk’s defence team, Prof Deakin said he had produced a report on the circumstances of the death in June 2020.

Prof Deakin, who works for the University Hospital Southampton NHS Trust and regularly flies with the Hampshire and Isle of Wight Air Ambulance, said two disease processes had led to Mr Atkinson having an enlarged heart.

Asked by defence QC Patrick Gibbs whether Mr Atkinson’s pre-existing health problems posed a high risk of sudden death, Prof Deakin told the court: “I think it’s always difficult to quantify these things…there are a lot of factors.

“Someone sitting quietly with their body not stressed is not at the same risk of death as somebody who has been undertaking some degree of physical activity.

“We need to consider the circumstances in which he found himself, both before and after the encounter with the police.”

Prof Deakin, who was asked for his views on 12 factors including the effect of pain caused by a 33-second Taser deployment, kicks and psychological stress, added: “It is very difficult to separate it all out.

“I think the complex interplay between all the issues we have talked about make it impossible to tease out any specific factor in terms of being certain of its exact contribution.

“The same risks that the tasering has produced were also produced by the physical exertion and stress beforehand. It really is impossible to distinguish the relative contributions of the two.”

Asked about the monitoring of Mr Atkinson by paramedics, Prof Deakin said he believed they had failed to appreciate the severity of his condition, and appeared not to have taken a blood pressure reading.

The witness said: “I think they may well have missed some of the early warning signs.”

The trial continues.