A man accused of murdering a home invader in Newcastle has said he only wanted the burglar to stop and meant him no harm, while a top pathologist has said a number of factors could have caused the death.

Key points: A man accused of murdering a home invader in 2016 says he "never intended to cause serious harm"

A man accused of murdering a home invader in 2016 says he "never intended to cause serious harm" A top pathologist says a number of factors could have contributed to the thief's death

A top pathologist says a number of factors could have contributed to the thief's death The defence intends to call witnesses who will speak to the character of the accused

Benjamin Batterham, 36, is being tried in the Newcastle Supreme Court over the 2016 death of Richard Slater.

It has not been disputed that Slater entered his alleged murderer's Hamilton home and stole his wife's handbag.

The court heard that following the burglary, Mr Batterham chased Mr Slater down the street and a struggle ensued.

Slater lost consciousness and died in hospital after his life support was turned off.

Accused 'never intended harm'

The crown alleges Slater was choked to death by Mr Batterham, but defence barrister Winston Terracini SC said he had toxic levels of ice in his system, was obese, and had a heart condition.

The crown wrapped up its case yesterday, and at the start of the defence case a statement penned by Mr Batterham was read to the jury.

"I am not guilty," Mr Batterham wrote.

"I never intended to cause Mr Slater any serious harm.

"He broke into my house, I began to chase him … I was calling for him to stop.

Ricky Slater, 34, died in hospital after being detained following the Hamilton break-in. ( Supplied )

"I wanted to apprehend him and get back was stolen.

"I admit I was angry and I hit him, but I was only trying to keep him from getting away.

"He was constantly struggling and fighting, he bit me on the right arm.

"All I wanted was for him was to stop."

'Multiple possible causes' of death

The defence has repeatedly claimed that Slater had a toxic level of ice in his veins, with a reading of 0.71 milligrams per litre.

Senior forensic pathologist Dr Johan Duflou, who is considered the state's top clinician in his field, said research had shown ice levels of 0.54 milligrams per litre had been attributed to causing death.

The court has previously heard Mr Slated died from multiple organ failure and Dr Duflou said he could not say that drug toxicity was solely to blame.

"There are multiple possible causes and they may all have interacted in some way or an other," he said.

"But there is always a possibility there was a single cause.

"I believe they all probably interacted in some way.

"I would include methamphetamine toxicity, I would include the fact that the deceased was held in a face down, prone restraint position, and if there was neck compression.

"I would consider heart disease, his obesity and excited delirium syndrome."

'They struggle, then suddenly stop'

Slater weighed 118 kilograms at the time of his death, and Dr Duflou said the syndrome, though a contested diagnosis in the medical profession, could have been deadly.

"I think some of the features may be the result of excited delirium," he said.

"It is fair to say what happens is that a person goes wild, becomes aggressive and has superhuman strength.

"There is quite strange behaviour and the danger is if you restrain a person like this and they have a heart condition there is a chance of cardiac arrest.

"They struggle, struggle, struggle, then suddenly stop.

"Is this a case of excited delirium? I don't know, but I raise it as a possibility."

Three heart attacks before death, court hears

The doctor also described the impact of the 330 metre foot chase Slater had been in before he died.

He said the case was similar to other deaths he had examined after a person with the same medical issues had been chased and brought down by police.

Beryl Dickson, the mother of Ricky Slater, and family members stand outside court in Newcastle. ( ABC News: Luke Rosen )

"A person who is … overweight, with [a] disease not known about, who takes a psychostimulant drug and is typically chased, held down, handcuffed, [then] at some stage the person has no pulse and has a cardiac arrest," Dr Duflou said.

The court heard Slater had three cardiac arrests before he died.

The defence has started calling its witnesses for Mr Batterham.

Mr Terracini said witnesses Mr Batterham is relying on to say he is of good character will take the stand.

"Their witnesses will talk about their knowledge and in their view that he [Mr Batterham] is not a violent or aggressive young man," Mr Terracini said.

The hearing continues.