• Roz Mexted from Westlake Girls High School to St Cuthbert's College (July 2016).
• David Hodge from Rangitoto College to a new role as head of St Kentigern's four Auckland schools (Feb 2017).
An associate principal from Westlake Boys' High School, Alex Reed, has also been appointed this year as principal of privately-owned Pinehurst School in Albany.
A state school principal said the remuneration being offered by top private schools was "reputedly very good; rumours of being up to twice the state sector".
Post-Primary Teachers' Association president Jack Boyle said private schools were "poaching" both principals and teachers from state schools.
"Our investigation around the [teacher] supply challenges came up with anecdotal stories from principals that high-decile schools were pinching teachers from lower-decile schools, and by the same token there was a suggestion that private schools were pinching both teachers and principals from high-decile [state] schools," he said.
He said private schools were generally better funded, leaving principals free to focus on educational rather than financial issues.
But Brooke, 54, who has been at Long Bay since 2004, said he was moving simply for "a different challenge".
"I have given my whole life to the state system. I have enjoyed every minute of it," he said.
"An opportunity came my way. It's an opportunity to do something different, I'm attracted by the new and different challenge."
Mexted, who headed Nga Tawa Diocesan School at Marton before moving to Westlake, said she was considering a move to Australia before the top job at St Cuthbert's became available.
She said Australian schools were "a lot more generous" and actively recruited in New Zealand.
"But it's not all about the money. I'd probably be over there if it was," she said. "I'm always wanting to be challenged."
Independent Schools of NZ director Deborah James said pay rates in the country's 86 private schools varied widely.
"I would be surprised if they paid double what an equivalent fulltime principal would get in the state sector, but that's not to say there might not be one or two that do," she said.
"The private school sector is very small in New Zealand so therefore arguably there isn't the talent pool where we could draw our principals from within the sector, and teachers and principals are very mobile moving from one school authority to another, so there is really nothing unusual about it.
"It's just that probably there have been a few more changes in the last two years than in the previous five or six years. It just seems to be cyclical."
Ministry of Education head of early learning and student achievement Karl Le Quesne said state school principals were "paid appropriately".
"At the bottom end, for the smallest secondary school, a principal starts at $90,007 and can go up to $116,782," he said.
"At the top end, for the largest secondary schools, a principal's pay starts at $200,211 and can go up to a maximum of $241,865."
Rangitoto College board of trustees deputy chairman Mike Shaw said a new Rangitoto principal would start on the base rate of $200,211, with potential bonuses that could take him to $241,865 at the board's discretion in future years.
In addition, since 2015 the ministry has been able to pay a "principal recruitment allowance" of $50,000 a year to principals with strong track records moving to head state schools with below-average student achievement or other serious problems.
Le Quesne said the ministry had spent $718,530 on recruitment allowances for 20 principals so far. Allowances have been approved for three other schools which are still recruiting new principals.
Principal Recruitment Allowances
Mangamuka School, Northland (principal appointed July 2015)
Note: Porirua College was also given approval to pay the principal recruitment allowance but appointed someone who had not been a principal before and so did not qualify for the allowance.