The Prime Minister is at the centre of an embarrassing disclosure in the midst of the Panama Papers leak.
Parliament's latest register of MPs' financial interests show John Key has a short term deposit with a company called Antipodes Trust Group.
The company advertises on its website that it is "a specialist provider of trustee and associated services for foreign trusts using New Zealand as their jurisdiction of choice."
Documents in the Panama leaks have made references to foreign trusts set-up here and Mr Key's political opponents say the trusts are shrouded in too much secrecy and effectively makes New Zealand a tax haven.
Mr Key has appointed businessman and tax expert, John Sherwan, to review New Zealand's disclosure requirements with foreign trusts.
Mr Key says the deposit with Antipodes Trust Group has shown up in this year's register of his pecuniary interests because, in the past 12 months, his long-time personal
lawyer went to work for the Trust Group.
Mr Key says the deposit is to cover any costs incurred by a family trust administered by his lawyer, Ken Whitney, and any surplus from the deposit is invested with New Zealand trading banks.
There is no evidence that either Mr Key, Mr Key's lawyer, or the Antipodes Trust Group have done anything illegal or are in any way linked to issues raised in the leaks of documents from Panamanian law firm Mossack Fonseca.
The millions of documents are said to make reference to New Zealand some 60,000 times, including email correspondence from Mossat Fonseca staff based here two years ago which said, "New Zealand has very weak laws in regard to due diligence, they only require utility bill and passport."
Mr Sherwan is due to report back by June 30.