Malaysian Prime Minister Najib Razak speaks at a news conference
Malaysian Prime Minister Najib Razak speaks at a news conference where he announced that two black boxes from downed Malaysia Airlines flight MH17 will be handed over to Malaysia by Ukrainian rebels, in Kuala Lumpur July 22, 2014. REUTERS/Olivia Harris(MALAYSIA) REUTERS/Olivia Harris

The Malaysian diplomat accused of sexual assault has not yet returned to New Zealand to face charges despite the Malaysian authorities' waiver of immunity. New Zealand Prime Minister Murray McCully said Muhammad Rizalman bin Ismail will return "sometime soon."

McCully told TVNZ that the government cannot determine the exact date of the diplomat's return since it is "completely in the hands of lawyers." He revealed he assured the Malaysian government that Rizalman will get a fair trial upon his return and not biased with "a lot of loose talk."

McCully explained that his job is to make sure the Malaysian government will continue to have confidence in New Zealand's justice system. He said he's not going to get involved in a "domestic debate" ahead of the September election.

When asked about the ministry's handling of the case, McCully blamed an "overworked staff member" who did not open a relevant email until the issue had become public in early July. McCully declined to discuss the issue of calls for his resignation in connection with the case.

The foreign minister said he has not watched the television interview of the Malaysian diplomat's alleged victim because he was busy trying to win New Zealand a seat in the UN Security Council. McCully believes New Zealand cannot buy its way to the council unlike other countries that spend millions.

Tania Billingsley revealed herself on television as the alleged victim of the Malaysian diplomat who is facing charges of assault, as legal experts have warned of endangering the suspect's fair trial. McCully was called to resign because of the way the government is handling the case.

Labour Party foreign affairs spokesman David Shearer may be on the verge of saying McCully should resign when he said the minister should acknowledge his failure. Shearer suggested McCully offer his resignation.

Shearer and the Greens have called for an external and independent review of the way the ministry handled the Malaysian diplomat's case.

McCully did not address calls for his resignation but only said he publicly apologised to Billingsley for the way the case was handled.

Billingsley, the 21-year-old Wellington woman who accused the Malaysia diplomat of following her home and assaulting her, appeared in an interview with television network TV3.