Mauha Huataki Fawcett, 26, denies murdering Miss Manning on or about December 18, 2008.
He is representing himself at a High Court murder trial which began in Christchurch today.
The Crown says Miss Manning was accused by the Mongrel Mob of owing them money when a group of gangsters raped, bashed, stabbed and strangled her before dumping her mutilated body in a river.
Fawcett, who has no legal training, stood in court today to make his opening address.
In a quiet and at times barely audible voice, Fawcett - known within gang circles as 'Muck Dog' or 'Little Muck Dog' - said he was "shocked" to be standing trial for murder.
He said he was not guilty, having played no part in her killing.
"I'm here charged for murder for what I've said [to police]," he said.
"I've made these false confessions, which was due to pressure put on by the police.
"I'm very shocked to be standing here today.
"This crime was totally out of character for myself."
He added that he was "ashamed of the justice" that has been brought before the court.
"That's all I want to say."
Earlier, the Crown in its opening address said Fawcett was a soldier, or prospect, for the Mongrel Mob.
His job was to mind the girls selling sex on Manchester St in Christchurch and to enforce taxes.
The court heard that the Aotearoa chapter of the Mongrel Mob was trying to muscle in and control the city's red light district, and wanted to tax the street workers $20 on each transaction.
Miss Manning - aged 27 - had been working on her usual patch on the corner of Peterborough and Manchester streets on the night she was killed.
The court heard she had entertained clients earlier that night, and the last known sighting of her by members of the public was around 10.35pm to 10.40pm.
In conflicting police interviews, Fawcett described how Miss Manning was taken to the gang pad at Galbraith Avenue, Avonside, in what was a planned hit.
He said he was supposed to stab Miss Manning in order to get his patch, the court heard.
The patch, he had been told by gang elders, gave them "licence to kill, to do anything", Ms Currie said.
Fawcett told police in an early interview that Mongrel Mob gangsters barked like dogs and gave Nazi salutes as they carried out the brutal fatal assault.
He heard Miss Manning say, "Bro, bro, what are you up to?" before she was knocked out by punches, Crown prosecutor Pip Currie said.
Another mobster turned up and took part in raping her, Fawcett claimed.
A metal pole with a hook in its end was produced and was used to beat Miss Manning as she tried to crawl away, the court heard.
Fawcett initially told police he was handed the pole and ordered to hit her.
"And so he shut his eyes and hit," the court heard.
Miss Manning was also stabbed, and a hammer was used by someone else to deliver the final, fatal blow, Fawcett allegedly told police.
"He said it was a blood bath," Ms Currie told the court.
All of the mobsters present had gloves on, Fawcett told police in that early interview, and he had helped dumped the body in the Avon River, just 200 metres from the gang pad.
They had put the bloodied body in a car which had a plastic blue tarpaulin in it, and he later wiped the car down with towels, he first told police.
At around 6.30am on December 19, 2008, Miss Manning's partially-naked body was discovered floating in the Avon River by a kayaker.
In a later statement Fawcett tried to backtrack from his earlier version of events, saying he hadn't been personally involved in the attack and that he was just a lookout, the court heard.
He said he didn't want to stab her and that others did.
"He said he was there, said 'Sieg heil', and started barking like others did during the assault," Ms Currie said.
He said he had lied in the hope he could get locked up and get away from the mob.
A post mortem examination identified four different types of injuries - all of which were life-threatening. They included blunt force head injuries, bruises indicative of strangulation, and stab wounds to Miss Manning's chest and elsewhere on her body.
The subsequent police investigation was "extensive and thorough", Ms Currie said, but was not without its difficulties, with many witnesses being people who usually didn't want to talk to the police.
Ms Currie said even if Fawcett's involvement was less than others, his actions are still enough to make him a party to and therefore guilty of murder.
"He was there either as a joint principle offender or as a party to her murder," Ms Currie said.
The trial, set down for six weeks with around 100 witnesses, continues before Justice David Gendall.
