Major had been set to go to trial on five representative counts of assault on a child aged under 14 but pleaded guilty when he was re-arraigned in Tauranga District Court yesterday.
The abuses occurred between January 2010 and February 2012.
The Crown summary of facts revealed that Child, Youth and Family service had several dealings with this family in relation to concerns over the care and protection of the children.
On February 15, as a result of information received, CYF staff and police went to the family's home armed with a court order and took the children into care.
During an interview on February 16 this year, the eldest victim told a CYF interviewer he and all his siblings, including the two youngest children, were kicked and hit by Major on a regular basis, and often he wore "metal boots" while doing so.
He also described the swimming pool incident and spoke about watching his 7-year-old brother being beaten and "smashed on the ground," and having his hair pulled out by Major because the sibling regularly wet the bed.
These "bad things" had happened most of his life, and there were "no good things" in their house.
Sometimes there was no food for them to eat, the boy said.
The next day the three eldest children were forensically interviewed about what had being going on in their home and Major's behaviour.
During the interview, the 6-year-old boy said Major and his mother constantly argued and fought, and Major regularly kicked him and his brothers "up the arse" and struck the three oldest boys with a plastic water pipe.
When asked how he felt about the abuses, the boy said he had been "sore and sad" and had been told not to talk about what had occurred by his parents as "we'd go to jail".
The 7-year-old recounted how Major would kick and slap him, and give him hidings, and how he was warned if "we don't shut up we would get more hidings".
He also described how Major would also pull his hair, sometimes pulling hair out, and he would be "booted in the arse" and sworn at.
He told the interviewer that he had seen Major and his mother fighting and had seen his mother punched in the head, and also talked about being told not to speak about what was occurring for fear of "getting a hiding".
He described a home environment involving violence, drug use, drunkenness and verbal abuse.
When questioned by police on February 22, Major said apart from verbally disciplining and very occasionally manhandling the children he had never struck, kicked or physically disciplined them.
Child, Youth and Family Operations general manager Marama Edwards said the children were safe and well in the care of the wider family.
She said they became involved with the family after one of the children disclosed physical abuse.
"We moved immediately to protect the safety all of the children and they were placed with approved caregivers," she said.
"Child, Youth and Family was not working with this family at the time the abuse was disclosed."
Major's partner denied any recent wrongdoing towards her and the children. Major was remanded in custody by Judge Robert Wolff pending sentencing on August 31.
