New Zealand First leader Winston Peters is joining calls for Justice Minister Judith Collins to be sacked.
Papers issued under the Official Information Act show the minister's office sought a briefing from the Ministry of Foreign Affairs and Trade before she attended a dinner in China with executives of the export company Oravida.
Ms Collins has been criticised over the dinner because her husband is on the company's board.
The papers show that two days after her office had initially consulted the Foreign Affairs Ministry, her office then said the dinner was a private engagement and no advice was required.
Mr Peters said this shows Ms Collins was favouring the company, but she says the briefing was sought by her staff, not her.