None have yet entered a plea.
Yesterday, lawyers for the three confirmed the case had passed through the committal phase of the court process, although no date had yet been set for trial.
MP Hone Harawira issued a statement on the matter this morning.
"Family remains a cornerstone of my life, through both the good times and the bad times. The matter relating to my nephews is before the court at this time and I'd rather not comment on the allegations until the case is over," he said.
"I have however, offered my help to settle this in the best interests of all parties concerned. That is all I have to say on the matter," he said.
Hinewhare Harawira refused to comment.
A source close to the Harawira whanau said matriarch Titewhai Harawira was furious when she heard about the alleged incident.
"She was disgusted by what happened."
Interviews with the men and the victim led to a police summary setting out the allegations against the three.
It alleged they had spent the early afternoon drinking at a relative's home in Blockhouse Bay before heading to a nearby beach on Manukau Harbour.
Also at the beach reserve was the 12-year-old boy, who was playing with a toy.
The men claimed that as they were leaving, they saw the boy "mouthing some words at them".
According to the police summary, they pulled the car over and gave chase, following the boy to his home before returning for the car and parking it in the driveway.
The police statement alleged Mau Harawira opened a ranchslider door and walked into the house shouting for the boy, who was in his bedroom.
Police alleged the boy was struck and thrown to the ground before Enesi Taito joined his brother and "punched and kicked the victim about the head and torso as he has lain on the ground" trying to cover his head with his arms.
The two men then dragged the boy out of his bedroom "by his hair and arms" and onto the deck, where Tohora Harawira was waiting, the police claimed.
Enesi Taito slapped the boy several more times while Mau Harawira went back inside the house and took a PlayStation3, games, two pairs of sport shoes and a baseball cap, the police summary claimed.
The boy pleaded for the men not to take his belongings.
Police alleged Mau Harawira replied: "Calm, calm, or I will beat you again."
The boy was taken to hospital for a check-up. Doctors found bruising to his cheek, nose and chest. He was discharged.
On a One News clip from Waitangi Day, Hinewhare Harawira said her family came in for attention and criticism because, she declared, "we've not only got a brain, we're good looking as well".
- NZ Herald with nzherald.co.nz