The principal of the privately-run Taranaki Green School, which became embroiled in controversy after receiving an almost $12 million government grant, has resigned only months into the job.
Since then, Green Party co-leader James Shaw has said the grant would now likely be a loan rather than grant.
In a statement, the school said Stuart MacAlpine had been headhunted by a "prestigious" - but unnamed - global foundation and would leave at the end of the year.
MacAlpine said although the goodbye was premature, he felt fortunate to have spent time at the school and worked alongside its founders, Mike and Rachel Perrett.
"I know the school will flourish in ways we cannot yet imagine with their leadership. I am profoundly grateful to them and chief executive Chris Edwards, who has been a mentor, friend and guide in my time here. I know we will be lifelong friends."
Edwards said the poaching of MacAlpine was an affirmation of the quality of the school's educational leadership team
"Stuart is considered to be one of the top educators and curriculum developers in the world and his curriculum work at Green School has been truly exceptional," Edwards said.
"It has been an honour to have him with us to set the foundation of Green School for our first year and really does validate the strength of the learning programme we now have in place."
MacAlpine would continue to be involved in the development of the school's curriculum after his departure, Edwards said.