Justice Minister Judith Collins said yesterday she would resign if it was proved she lobbied a Chinese official on behalf of food exporter Oravida at a dinner in Beijing last year.
Under further Opposition pressure over her links to Oravida's founder, Deyi "Stone" Shi, Ms Collins was uncharacteristically subdued.
On Wednesday, Prime Minister John Key publicly expressed his ire that she had been economical with the truth about meetings with Mr Shi while visiting China last October.
She revealed that apart from a previously disclosed visit to milk exporter Oravida's Shanghai offices, she dined with Mr Shi, the company's managing director Julia Xu, and a senior Chinese border control official while in Beijing.
Mr Key has accepted Ms Collins' assurances that Oravida's business was not discussed at the dinner, but yesterday, New Zealand First leader Winston Peters challenged that in Parliament.
"Following the botulism scare of last year, is it not a fact that her visit to Oravida was predominantly access and Customs clearance for Oravida products in the Chinese market, and that is the real reason why a People's Republic of China border official was present at that dinner?"
Ms Collins once again denied that, and when asked if she would resign if it emerged that she discussed Oravida's imports to China with the border official, said: "Yes, of course, but I didn't."
Ms Collins said her senior adviser Margaret Malcolm, who was also present at the dinner, would confirm that Oravida's business was not discussed, which is exactly what Ms Malcolm did when contacted by the Herald.
Asked whether Ms Xu had ever raised concerns with her about problems getting product into China, Ms Collins said no.
"They were not affected by the whey powder. They're the first exporters of fresh milk from New Zealand to China and this was not affected by Fonterra."
However, that is at odds with a television interview Ms Xu gave a month before the Beijing dinner.
Ms Xu said that in the wake of the Fonterra botulism scare her company, which exports milk and other products to China, was facing additional stringent testing requirements from the Chinese border control agency CIQ (China Inspection & Quarantine Services). That added costs and caused delays.
During the interview on TVNZ's Q+A Ms Xu also said: "I think the Government, perhaps, could do a little more to engage in more bilateral talks to remove some of the tests or measures the Chinese Government have put on because of this false mistake."
Ms Collins refused to identify the Chinese border control official who was at the dinner or say which agency they worked for, and indicated she was being kept on a short leash by the Prime Minister.
"I think you should talk to the Prime Minister's office because I am giving you the words that I have been told that I should say, otherwise there could be an issue with China."
Yesterday, Ms Collins appeared to be close to tears when asked by reporters about suggestions from Labour MP Shane Jones that she had been staying at Mr Shi's home - the Paritai Drive mansion partly financed by Mark Hotchin.
"I'm really disgusted, actually, that Shane would do that. It's actually really hurtful. I've been to the home that Mr Shi has bought on many occasions because he is a close personal friend and he's away a lot but I've never lived there. I don't stay there.
"I never put the boot into Shane and yet he's gone and done that. That's disgusting."