Before he left the country with the children the woman secretly accessed his emails and found out about his plan to break up the marriage.
"He had said to his parents that he had no wish to return to Abu Dhabi after the Christmas holiday," a court document stated.
As a result, the woman drew up an agreement for him to sign stating he would return them to their home in Abu Dhabi after the holiday.
"Should either party break the terms set out in this contract, it will be automatically taken as ... the parent has unlawfully abducted [the children] against the other parent's will," that agreement said.
The pair both signed the document and he left with the children two days later.
But he did not return to Abu Dhabi as promised and the children's mother filed an application in the High Court at Christchurch under the Habeas Corpus Act 2001 to force their return home.
The Act effectively provides the High Court to order the restoration of liberty of a person found to be unlawfully detained.
In a decision released today Justice Gerald Nation granted the mother's application and ordered the children to be returned.
For legal reasons the names of the children cannot be published, meaning the Herald cannot identify the parents.
The estranged couple met in 1999 when the woman, from Sweden, met the man in London.
They married in 2005 and during the course of their relationship they lived in the Caribbean, Australia, Dubai, Thailand and Malaysia before making a home in Abu Dhabi.
In mid-2015 the couple started having relationship problems and the woman was made redundant from her job, which did not help the situation.
They agreed to stay together and "try and patch things up for the sake of the children" and they moved to Abu Dhabi for a fresh start.
The children thrived in their new home, making friends, excelling at school and sport.
Justice Nation said there was "undisputed" evidence that the man and woman were both involved in co-parenting the children, who were "well adjusted" and "without major problems".
The father told the court he had no safety concerns for his children while they were in their mother's care.
After deciding not to return the children the man initially told his wife that he was "extending their holiday".
Then, on January 27 he advised her during a phone call that he was not bringing the children home at all.
The court heard that the man advised the children's schools that they were not coming back, and was taking advice on "how to progress his intentions over a separation".
"In an email to his parents of 8 November 2016, [he] said he had three options. Option one was to prepare and present a proposal to [his wife] which would keep him in Abu Dhabi in the short-term with the children," Justice Nation said.
"Option two was to seek the assistance of Abu Dhabi courts in the hope of obtaining support for his move back to New Zealand with the children.
"Option three was to go to New Zealand with the children and not come back. In that regard, he noted there was no Hague Convention agreement with the UAE and that there were obvious negatives with this option but it could be used as a last resort."
The Hague Convention on the Civil Aspects of Child Abduction is an international agreement among a number of countries aiming to ensure that children who are taken or kept overseas are returned as quickly as possible to the country in which they usually live.
Justice Nation said the agreement he couple signed before the man left Abu Dhabi was clear.
"I am satisfied that both parties would have understood that it meant, in the event of either party not returning with the children to Abu Dhabi after taking them from Abu Dhabi for a holiday, they would be obliged to bring the children back ... and to have any dispute over their non-return determined while the children continued to reside in Abu Dhabi," he said.
He clarified it was not his role to decide where the children should live permanently, or any custody matters, and any further decisions about their future should be made by the courts in Abu Dhabi.
"I consider the children have been unlawfully detained in New Zealand," he said in his decision.
"I am satisfied that [the man's] retention of the children in New Zealand was in breach of the agreement the parents entered into.
"On that basis, [he] has not satisfied me that his detention of the children in New Zealand is lawful."
The man returned to Abu Dhabi with the children in late February.
