The results of a ministerial inquiry into the case of a Malaysian diplomat who left the country with immunity are "disappointing", Foreign Minister Murray McCully says.
The minister had been advised not to release the report by former Treasury Secretary John Whitehead until court proceedings against former defence attache Muhammed Rizalman bin Ismail were completed.
Mr McCully said the conclusions reached by Mr Whitehead were "not surprising, but they are disappointing".
"At the heart of the matter is a single email, events surrounding which are carefully canvassed by Mr Whitehead's report."
He said that because of a number of "procedural shortcomings", the Ministry of Foreign Affairs and Trade (Mfat) led the Malaysian Government to believe that Rizalman could return to Malaysia despite facing assault charges.
Mfat's actions were contrary to "the long-standing policy of the New Zealand government on diplomatic immunity".
Mr McCully said the report contained 21 recommendations. He had forwarded these to Mfat chief executive John Allen and had asked him to implement all of them.
Mr Rizalman is facing charges of assault with attempt to rape and burglary following an attack on Wellington woman Tania Billingsley at her home in May.
He left the country two weeks after the alleged assault following the botch-up by Mfat.
Mr McCully said he would leave it to Mr Allen to consider any disciplinary actions which stemmed from the inquiry.
An Mfat official who was allegedly involved in the confusion, deputy chief of protocol Mary Oliver, left the job last month.
Prime Minister John Key did not criticise Ms Oliver directly at the time, but said any official who did not clearly give the impression that New Zealand wanted Rizalman tried here needed "to think very strongly about whether they're in the right job".
The Malaysian Foreign Minister claimed it was at a meeting between Malaysian and New Zealand officials including Ms Oliver that New Zealand offered an "alternative" for Rizalman to be returned to Malaysia in May.
Since coming back to New Zealand in October, Rizalman has pleaded not guilty to the charges. He has been bailed and will appear in court again in February.