Mr Kun's Nauruan passport was cancelled amid accusations he had taken part in protests outside parliament - which he denies - and he had been unable to leave the country.
He applied for New Zealand citizenship in December last year in order to join his family in Wellington.
His lawyer, Claudia Geiringer, said his New Zealand passport was issued twelve days ago and sent to Nauru.
Its like something out of the Cold War - Kun had to check in at the last minute to avoid being detained at the airport. But now he's safe. Its something the government should have done a long time ago, but I guess accepting NZ citizenship would have meant publicly surrendering his seat in Parliament (which he wasn't able to take anyway). Waiting until the election (which the government has predictably won, having locked the opposition out of the media) looks to have been a good way to get away with it.
It is terrible that we're having to do this sort of thing in the Pacific, and we should be clear about who is to blame: Australia. Their blood money for hosting a refugee concentration camp has destroyed Nauru's democracy and turned it into a repressive regime. The sooner they close that camp, the better.