New Zealand Ministry of Foreign Affairs and Trade (MFAT) chief executive John Allen today apologized to the government for the confusion in the dealing with the case of the Malaysian diplomat accused of sexual assault.

The New Zealand Herald reported that it issued a public apology "to acknowledge shortcomings in the advice provided by the ministry and also its management of a serious incident".

"The ministry has fallen well short of its obligations to the Government on this occasion and we take this failure very seriously," Allen said.

"It is the longstanding policy of the New Zealand Government to formally request the waiver of diplomatic immunity in such cases.

He said the ministry will be conducting a review process withing the ministry "to reassess our policy and procedures for handling similar situations" and was likely to be independent.

The review is expected to focus on two areas specifically the informal communication with the Malaysian high commission which led to a different course of action expected by the New Zealand government and the fact that the minister was not briefed about the events sufficiently.

Earlier today Foreign Minister Murray McCully has publicly apologised to Prime Minister John Kerry for not providing him with all the information surrounding the case of a Malaysian foreign diplomat before speaking on the matter publicly.

McCully also extended his apology to the victim for the actions taken which fell below the expected standards.

"I have made it clear that we apologise for a performance that was below the standard that should be expected of the New Zealand Foreign Ministry.

Murray explained that he has tried to identify who knows about this incident and when.

He explained that he was not informed Malaysia had rejected the request for Muhammed Rizalman Ismail, a Defence Ministry staff, waiver of diplomatic immunity until last week, more than a month after Rizalman left New Zealand.

"To the best of my knowledge, certainly quite a number of people in the ministry were copied in [to correspondence]," McCully said.

He was informed that one member of his staff did receive an email about the matter "and did not open it.

She was apparently travelling in a place where there was no communication capability at the time.

"Other members of my staff, who should have been copied in, were not."