John Key once described British Prime Minister David Cameron as the global leader he most admires, but he is refusing to comment on allegations Mr Cameron put his genitals in a dead pig's mouth during his time at university.
When questioned on how he felt about the allegations, Mr Key said: "I don't have any interest in going there."
He was also not prepared to comment on whether Lord Ashcroft had ever discussed his feelings about Mr Cameron with him.
Lord Ashcroft co-authored the new biography which makes the allegations, and warns photographic evidence could surface.
The book also claims David Cameron was a regular smoker of marijuana.