Labour leader Andrew Little is calling on Prime Minister John Key to release his personal tax records.
Documents leaked from a Panamanian law firm last week revealed how the world's wealthy set up tax shelters to hide their assets.
The scandal has hit some world leaders including Iceland's Prime Minister Sigmundur David Gunnlaugsson and the British Prime Minister David Cameron.
Mr Little has since agreed to release his tax details back to about 2010, and says Mr Key should do the same.
"He is our Prime Minister now and he is dealing with an issue about tax and the morality of tax dodging.
"I think to give New Zealanders an assurance that he is squeaky clean and above board he should be disclosing his tax records, in just the same way that David Cameron has just agreed he is going to disclose his."
But Mr Key has said he complied with the law governing disclosure of financial interests and did not believe it was necessary to release his tax records.
"It would have to be a pretty big step, I think, to move in that regard.
"It wouldn't solve the issues that people would want. They'd ultimately want all sorts of other disclosures around trusts and other things and you can start moving into spouses - we have a pecuniary interest list, we follow that carefully, people have to be judged by what they ultimately do."