Former Dilworth assistant principal and convicted sex offender Ian Wilson has pleaded guilty to 19 fresh charges.
Wilson appeared via audio-visual link before Judge Glubb at Auckland District on Thursday morning.
He appeared on multiple indecent assault charges related to offences against five complainants aged 16 or under at the time.
The offending spans decades, with indecent acts committed in places such as sick bays and camps.
He will be sentenced in August.
Wilson was previously sentenced to jail in March 2021 for three years and seven months for indecently assaulting five students.
Wilson's offending spanned more than a decade and involved many victims. It started in the late 1970s, when Wilson was 22 or 23, and continued until 1992, when he was in his early 30s.
Wilson is one of seven men charged in relation to alleged historical abuse at the Auckland school.
When Wilson was sentenced in 2021, victims delivered powerful impact statements in court.
Neil Harding, one of Wilson's victims, spoke directly to his abuser, asking Wilson: "Did you not consider I would grow up and remember your actions?"
"You're sitting there and I'm sitting here. It feels good, it feels right."
Harding was 11 years old when he went to Dilworth School.
Victim A, whose statement was read by a prosecutor, said his first time being assaulted was when the school was empty and quiet. He said it continued for four and a half years, at an average of two and a half times a week.
He said he tried to tell a priest about the abuse but was called a stupid boy and a liar.
"I couldn't complain to anyone - I had nowhere else to go," he said.
"Emotionally I was a wreck. Financially, mentally [it] changed my entire life and sent me in a direction that almost anyone would fail at.
"I found some peace with Wilson's guilty plea... Wilson changed my life and I'll always wonder how my life could have been."
