The government of Nauru is being told to grow up after it lashed out at New Zealand over last year's decision to suspend its justice aid funding.

Last September the New Zealand government put a stop to over a million dollars worth of support for Nauru's legal sector because of the way the government was using its justice system against opposition MPs and its political opponents.

The papers, released under the Official Information Act, reveal our government was warned there'd be a push back from Nauru if its aid funding was suspended.

The Ministry of Foreign Affairs and Trade documents show both Nauru's President, Baron Waqa and its Justice Minister David Adeang attacking New Zealand's decision.

Adeang accused New Zealand of using the justice funding to buy the release of opposition MP Roland Kun, while the country's President has said Kun encouraged New Zealand to freeze the funding as part of treasonous acts.

Labour Party Foreign Affairs spokesman David Shearer said the comments show a lack of maturity, pointing out the aid was suspended because Nauru's Government was acting illegally and unconstitutionally.

"I think that that was completely and utterly appropriate. Now for them to come back and have a go at us like this, misses the point that the Government needs to act more responsibly and more democratically."