He assumed Immigration NZ gave it careful consideration and did not have a problem with Ms Lawson's approval if that was the case.
"I hope it's not simply because been given because Nigella is a celebrity, and she was subject to the same rules as others are. But if special circumstances are present, I accept that."
His main concern was over consistency in applying exemptions to visa requirements, saying Immigration ministers had refused to intervene in the case of Fijian Sunal Kumar, 30, who needs a kidney transplant, has raised the money and found a donor but has been told to return to Fiji by Thursday or be deported.
"Here is a life or death situation and you might have hoped, given it is at no cost to the state, for some compassion but the minister refuses to intervene. Where is the consistency?"
Associate Immigration Minister Nikki Kaye said she could not comment on the individual circumstances in each case.
"Generally, I think it is unhelpful to compare cases as each case will involve different circumstances and information that will be weighed up in the decision making process."
She said ministers were not involved in the decision on Nigella Lawson. That decision was made by officials rather than ministers because involved a temporary visa.
Ministers are usually only involved in exercising the discretion in cases where residency is an issue.
Immigration NZ would not say what specific issues they had considered in making the decision relating to Ms Lawson.