In the House, Labour MP Grant Robertson asked her whether the official worked for China's Administration of Quality Supervision, Inspection and Quarantine (AQSIQ). The agency last year left thousands of tonnes of New Zealand meat exports sitting on Chinese wharves through a paperwork problem. The Opposition claims that Ms Collins' dinner with the border control official was intended to help Oravida get its milk into China.
But Ms Collins, who denies Oravida's milk imports were discussed at the meeting, once again said it was "a private dinner for which I do not have ministerial responsibility".
Mr Robertson later told the Herald Ms Collins "had the opportunity to rule out that the official at the meeting was from the agency responsible for letting Oravida's goods into China. She didn't do that. I think we can make a fairly safe assumption that is exactly where the official was from and that raises the conflict of interest because we know that Oravida were lobbying to try and get their products into China".
But Mr Key said whether the official worked for AQSIQ was "not relevant and that's the advice I've had from the Cabinet Office".
If it was proved that border control issues were discussed at the dinner, "that would be a problem", Mr Key said. "But I don't think that's going to be the case."
With just another day in Parliament before the Easter weekend, which looks likely to rob the Opposition's attacks of momentum, Ms Collins told the Herald: "I have the confidence of the Prime Minister and I have the confidence of the people I work with. I am going nowhere."
Ms Collins said she was unaware Oravida was having any problems getting its products into China at the time of the dinner. That was in spite of her husband David Wong Tung being on Oravida's board and the fact Mr Shi and Oravida's managing director, Julia Xu, were "close friends".
"My close friends get to see me on rare occasions because I am working most of the time and when I am with my friends we're talking about things that are fun things, not about problems at work."
Meanwhile, Mr Key confirmed Oravida had received several thousand dollars in taxpayer-funded compensation after the botulism scare.
The compensation decision was not made by ministers.