Details have finally emerged about a brutal alleged gang-related murder at a Christchurch community housing where a man was attacked with a hammer and repeatedly stabbed before his carotid artery was cut.

And it can now be revealed - after suppression around the facts of the case lapsed - that the cousin of a senior Mongrel Mob gang member and a young man living at the patched member's home - are allegedly behind the violent crime.

Both men admit their fatal attack on Brendon Ross in his own home, but deny the charges of murder they are each facing.

Ross, 50, died in his studio unit within a Kainga Ora community housing complex on Riccarton Rd on the night of March 4 last year.

He had been hit multiple times around the head and back with a hammer and stabbed repeatedly in the neck.

Curtis Taila Wealleans and Juan Isaacs Marsh, also known as Joseph Mahi, were charged with murder soon after.

The pair are on trial in the High Court at Christchurch before Justice Gerald Nation and a jury.

Juan Marsh in the dock in the High Court at Christchurch. Photo / George Heard

Both men admit attacking Ross - Wealleans with the hammer and Marsh with the knife - but say they did not intend to kill him.

Until now details of the alleged murder have been suppressed.

Crown prosecutor Mark Zarifeh outlined what happened to Ross, and why.

Family and friends of Ross sat in the public gallery listening to the graphic details.

Zarifeh said before he died Ross had a relationship with a woman who lived at the same housing complex.

When it ended the pair "developed an intense dislike for each other" and argued frequently.

"There were a number of acrimonious arguments between them, leading to the police being called," said Zarifeh.

Ross and a friend of his reportedly "abused and harassed" the woman often and the feud became "quite vicious".

Marsh was a friend of the woman and witnessed some of the abuse. He became became "increasingly frustrated and angry", said Zarifeh, and took matters into his own hands.

Days before the alleged murder Marsh messaged the woman and said "karma is coming round with bark and bite".

"This will be all over before you know it," he told her.

Murder accused Curtis Taila Wealleans. Photo / George Heard

Zarifeh said Marsh turned to his cousin Raihania "Ra" King - a senior member of the Mongrel Mob Aotearoa chapter in Christchurch.

"The Crown case is that Mr Marsh wanted someone to back him up on that visit to Mr Ross and he's likely to have met Mr Wealleans through his connection to Mr King," he said.

Wealleans was living in a sleepout at King's property on Maces Rd in Bromley.

The jury heard that on March 4 Marsh drove his female friend to a house in Spencerville where she spent the night.

He then went to Maces Rd and picked up Wealleans.

The pair, armed with their weapons, bought cans of bourbon and then went to the Kainga Ora complex.

They found Ross' unit - helped by a text from the woman confirming the number - and "set upon him".

"When these two men left the unit only minutes later, Brendon Ross was lying there dying," Zarifeh told the jury.

The Crown alleges Marsh tried to force his way into Ross' friend's unit and when he could not, said he would "be back later to get him".

When he left the friend rushed to Ross' unit and found him "mortally wounded".

He called 111 but Ross' injuries were not survivable and he was pronounced dead at the scene.

The jury heard how after the alleged murder Marsh dropped Wealleans off in Bromley and drove to the Port Hills and dumped bloodied clothing, wipes, seat covers from his car and the knife.

He then drove around the city before going to McDonald's to "get a feed" and returned to his home at Wigram.

After the alleged murder Marsh texted one person saying "done" and texted King about Wealleans using common Mongrel Mob wording.

The Herald will not publish those words.

Wealleans texted his partner and said: "I might have killed someone last night, I'm not lying, I'm not kidding… delete this message now."

When spoken to police both men denied any involvement.

They later admitted being at the unit and attacking Ross.

Police recovered the knife used by Marsh and Wealleans' hammer, which he hid in a fishpond at King's property.

Zarifeh told the jury they would be shown photos of the scene and hear details of the post-mortem examination carried out to establish Ross' injuries and cause of death.

They will also hear accounts from a number of people about the lead-up to the alleged murder, the night of the attack and the aftermath.

Zarifeh said some of the evidence would be "unsettling and upsetting".

He told them they had to put any feelings of prejudice aside in terms of the accused men, gangs, and Ross including how he behaved after his relationship ended.

Zarifeh said the Crown did not have to prove murderous intent, it was enough to prove that "death was likely" after the assault.

He said Marsh was the "principal offender" because he "wielded the knife" that inflicted the fatal injury.

"He hit Brendon Ross with the hammer but didn't use the knife. Under our legal system it's not only the person who caused the lethal injury that can be guilty of murder.

"A defendant can be found guilty as a party to murder if he intentionally aided or abetted Mr Marsh to commit the offence.

"The alternative is that Mr Wealleans could be a party to the offence if he and Mr Marsh formed a common intention, so they agree, to carry out an unlawful purpose.

"If they assist each other, each are a party. The Crown says Mr Wealleans would be guilty of murder. [He] agreed to go with Mr Marsh, he assisted in the attack and despite knowing there was lots of blood and Brendon Ross [needing] help, he's joined in and attacked with a hammer.

"The Crown says at the very least he's guilty as a party."

Zarifeh said the jury would need to be sure beyond reasonable doubt.

Both defence lawyers made brief opening statements.

Marsh's lawyer Paul McMenamin said his client did not mean to stab Ross - it was an unfortunate "accident" while they were "rolling around on the floor" during a fight.

He asked the jury to keep an open mind, particularly when faced with "disturbing" evidence.

"I ask that you wait patiently until the end of the trial until you decide," he said.

"I ask you to try and resist responding emotionally to the evidence."

For Wealleans, lawyer Craig Ruane said: "This is not a gang trial, this is not a mob hit. The involvement of the Mongrel Mob is peripheral but it doesn't cast an umbrella of gang violence over the events.

"Keep an open mind, then go away and make your decision, don't attempt to make a decision now."

The trial, set down for two weeks, continues.

Details have finally emerged about a brutal alleged gang-related murder at a Christchurch community housing where a man was attacked with a hammer and repeatedly stabbed before his carotid artery was cut.

And it can now be revealed - after suppression around the facts of the case lapsed - that the cousin of a senior Mongrel Mob gang member and a young man living at the patched member's home - are allegedly behind the violent crime.

Both men admit their fatal attack on Brendon Ross in his own home, but deny the charges of murder they are each facing.

Ross, 50, died in his studio unit within a Kainga Ora community housing complex on Riccarton Rd on the night of March 4 last year.

He had been hit multiple times around the head and back with a hammer and stabbed repeatedly in the neck.

Curtis Taila Wealleans and Juan Isaacs Marsh, also known as Joseph Mahi, were charged with murder soon after.

The pair are on trial in the High Court at Christchurch before Justice Gerald Nation and a jury.

Both men admit attacking Ross - Wealleans with the hammer and Marsh with the knife - but say they did not intend to kill him.

Until now details of the alleged murder have been suppressed.

Crown prosecutor Mark Zarifeh outlined what happened to Ross, and why.

Family and friends of Ross sat in the public gallery listening to the graphic details.

Zarifeh said before he died Ross had a relationship with a woman who lived at the same housing complex.

When it ended the pair "developed an intense dislike for each other" and argued frequently.

"There were a number of acrimonious arguments between them, leading to the police being called," said Zarifeh.

Ross and a friend of his reportedly "abused and harassed" the woman often and the feud became "quite vicious".

Marsh was a friend of the woman and witnessed some of the abuse. He became became "increasingly frustrated and angry", said Zarifeh, and took matters into his own hands.

Days before the alleged murder Marsh messaged the woman and said "karma is coming round with bark and bite".

"This will be all over before you know it," he told her.

Zarifeh said Marsh turned to his cousin Raihania "Ra" King - a senior member of the Mongrel Mob Aotearoa chapter in Christchurch.

"The Crown case is that Mr Marsh wanted someone to back him up on that visit to Mr Ross and he's likely to have met Mr Wealleans through his connection to Mr King," he said.

Wealleans was living in a sleepout at King's property on Maces Rd in Bromley.

The jury heard that on March 4 Marsh drove his female friend to a house in Spencerville where she spent the night.

He then went to Maces Rd and picked up Wealleans.

The pair, armed with their weapons, bought cans of bourbon and then went to the Kainga Ora complex.

They found Ross' unit - helped by a text from the woman confirming the number - and "set upon him".

"When these two men left the unit only minutes later, Brendon Ross was lying there dying," Zarifeh told the jury.

The Crown alleges Marsh tried to force his way into Ross' friend's unit and when he could not, said he would "be back later to get him".

When he left the friend rushed to Ross' unit and found him "mortally wounded".

He called 111 but Ross' injuries were not survivable and he was pronounced dead at the scene.

The jury heard how after the alleged murder Marsh dropped Wealleans off in Bromley and drove to the Port Hills and dumped bloodied clothing, wipes, seat covers from his car and the knife.

He then drove around the city before going to McDonald's to "get a feed" and returned to his home at Wigram.

After the alleged murder Marsh texted one person saying "done" and texted King about Wealleans using common Mongrel Mob wording.

The Herald will not publish those words.

Wealleans texted his partner and said: "I might have killed someone last night, I'm not lying, I'm not kidding… delete this message now."

When spoken to police both men denied any involvement.

They later admitted being at the unit and attacking Ross.

Police recovered the knife used by Marsh and Wealleans' hammer, which he hid in a fishpond at King's property.

Zarifeh told the jury they would be shown photos of the scene and hear details of the post-mortem examination carried out to establish Ross' injuries and cause of death.

They will also hear accounts from a number of people about the lead-up to the alleged murder, the night of the attack and the aftermath.

Zarifeh said some of the evidence would be "unsettling and upsetting".

He told them they had to put any feelings of prejudice aside in terms of the accused men, gangs, and Ross including how he behaved after his relationship ended.

Zarifeh said the Crown did not have to prove murderous intent, it was enough to prove that "death was likely" after the assault.

He said Marsh was the "principal offender" because he "wielded the knife" that inflicted the fatal injury.

"He hit Brendon Ross with the hammer but didn't use the knife. Under our legal system it's not only the person who caused the lethal injury that can be guilty of murder.

"A defendant can be found guilty as a party to murder if he intentionally aided or abetted Mr Marsh to commit the offence.

"The alternative is that Mr Wealleans could be a party to the offence if he and Mr Marsh formed a common intention, so they agree, to carry out an unlawful purpose.

"If they assist each other, each are a party. The Crown says Mr Wealleans would be guilty of murder. [He] agreed to go with Mr Marsh, he assisted in the attack and despite knowing there was lots of blood and Brendon Ross [needing] help, he's joined in and attacked with a hammer.

"The Crown says at the very least he's guilty as a party."

Zarifeh said the jury would need to be sure beyond reasonable doubt.

Both defence lawyers made brief opening statements.

Marsh's lawyer Paul McMenamin said his client did not mean to stab Ross - it was an unfortunate "accident" while they were "rolling around on the floor" during a fight.

He asked the jury to keep an open mind, particularly when faced with "disturbing" evidence.

"I ask that you wait patiently until the end of the trial until you decide," he said.

"I ask you to try and resist responding emotionally to the evidence."

For Wealleans, lawyer Craig Ruane said: "This is not a gang trial, this is not a mob hit. The involvement of the Mongrel Mob is peripheral but it doesn't cast an umbrella of gang violence over the events.

"Keep an open mind, then go away and make your decision, don't attempt to make a decision now."

The trial, set down for two weeks, continues.