Qld man's skull a 'voice from the grave'

Nicholas Collins' badly bashed skull is a "voice from the grave" to the jury which is about to decide his alleged murderer's fate, a court has heard.

Hamish Stewart Murray, 39, is accused of bludgeoning Mr Collins to death with a hammer in November 2012, five months before his skeletal remains were found in far north Queensland mangroves.

In closing submissions on Tuesday, Prosecutor Todd Fuller QC told the Cairns Supreme Court it had taken about 20 minutes for Collins' life to slip away.

"That is Nick Collins' voice in this trial, speaking to you from the grave about what happened to him," Mr Fuller said while pointing to diagrams of the injuries inflicted on the 30-year-old's skull.

"He tells us that his death was a violent one. That it involved severe force being delivered to his head on multiple occasions."

Murray admits to the killing but says it was in self-defence after Mr Collins, who had taken ice in the hours before the assault, choked him unconscious.

He says he hit him twice with the tool and later pushed him, causing Mr Collins to hit his head on a wall and table.

Defence barrister Joshua Trevino said his client wasn't to know that his instinct to push Mr Collins would result in the man's death.

He read out Murray's evidence at trial that he thought he was going to die and was the most frightened he'd ever been during the alleged attack by Mr Collins.

"The crown has failed in this case to rule out the possibility of self defence beyond reasonable doubt," Mr Trevino said.

The Crown's case has relied upon the evidence of 42-year-old Marnie Peckham, who is serving a jail sentence for helping Murray move the body and clean up the murder scene.

Mr Trevino told the jury her evidence, including that she heard Mr Collins being hit and found Murray with a hammer in his left hand, was inconsistent and unreliable.

"The reality is Marnie Peckham involved herself in the events downstairs (where the assault occurred)," Mr Trevino said.

"And while giving evidence, she has attempted to downplay that."

Mr Fuller asked the jury to dismiss Murray's evidence as "nonsense" and questioned whether he would have attempted to revive Mr Collins before "unceremoniously placing him in the mangroves".

Justice James Henry is expected to finish giving directions tomorrow before the jury retires to consider a verdict.