Former military attache Muhammad Rizalman has pleaded guilty on a charge of indecent assault.

The woman attacked in her Wellington home by a former Malaysian High Commission military attache is "really pleased" he pleaded guilty on Monday morning, the day he was due to go on trial.

Muhammad Rizalman bin Ismail, 39, was due for a three-week jury trial on Monday charged with indecent assault, assault with intent to commit sexual violation and burglary by remaining in a building on May 9, 2014.

On Monday morning, he pleaded guilty in the High Court at Wellington to indecent assault and the other two charges were dropped. Rizalman's lawyer, Dr Donald Stevens QC, told Justice David Collins that his client would change his not-guilty plea to indecent assault.

David White/Fairfax NZ Former military attache Muhammad Rizalman pleads guilty on November 30 to attacking a woman in her Wellington home.

A key supporter of Tania Billingsley, who earlier waived her right to name suppression, said the victim was thrilled with her attacker's guilty plea.

"She's really pleased with that outcome and really just thankful she has had such wonderful support at this time."

She was also "extremely grateful" that she would not have to go through a trial, said the supporter, whose name remained suppressed by the court.

3RD DEGREE/TV3 Victim Tania Rose Billingsley

"She had been extremely anxious about [a trial] because you are walking into the unknown."

The supporter said Billingsley had authorised her to comment to media on her behalf and did not wish to comment publicly herself while legal arguments about the case were ongoing, nor to attend court hearings.

"Until she is required to attend [court], she won't."

ALMOST NAKED

The court heard on Monday that Rizalman was almost naked when he confronted Billingsley in her home. He was arrested on May 10, 2014, following the attack in Billingsley's home in the Wellington suburb of Brooklyn.

Stevens asked the judge not to enter a conviction, saying he would be asking for a discharge without conviction on the charge.

A trial was expected to hear from Billingsley, witnesses and doctors about Rizalman's behaviour that night.

A statement of facts was read to the court, then interpreted into Malay for Rizalman.

It said Billingsley had been home alone watching a movie in her bedroom. Rizalman took off his trousers and underwear before going into the house through the closed but unlocked front door.

In the kitchen he then took off his jacket before knocking on her partially open bedroom door and pushing it open.

He asked her if he could come in.

Billingsley looked up and saw him wearing only a shirt and naked from the waist down. She screamed at him to leave. Rizalman put his hands on her shoulders but she managed to push him into the living room, then out of the flat before locking him out.

She then locked herself in the bathroom and called police. A flatmate's boyfriend arrived home and challenged Rizalman, who was still outside the front door.

Billingsley suffered bruising to her forearms and emotional trauma.

Rizalman began walking away but was stopped down the road by police.

He told police they had been at the cinema earlier in the day and Billingsley had invited him back to her home, but she had become angry with him for eating her food.

DIPLOMATIC ROW

After his arrest, Rizalman became the centre of a political furore by leaving New Zealand under diplomatic immunity.

He left New Zealand without facing trial after Malaysia invoked diplomatic immunity - in the belief it did so with the blessing of the New Zealand Government.

He returned to New Zealand escorted by police after extradition hearings were filed in Malaysia.

Stevens told the judge some of the facts of the case were still disputed by Rizalman. The case will be before the court again on Friday.

He said there was an issue over why Rizalman went into the house, whether there was any sexual intent and over his mental health.

An issue to be explored was Billingsley's statement that said Rizalman had tried to reach for her throat. Stevens said from the defence point of view Rizalman's hand may have come into contact with her throat during the struggle in the living room.

Crown prosecutor Grant Burston said it was not accepted that Billingsley may have touched him first in the bedroom as she was trying to get him to leave.

He described her as very, very frightened and the "fear slash terror" she was in because he was remaining in the house without leaving.

Burston said it was also not accepted that there was no sexual motivation or that he was suffering from a significant mental illness. One expert had said his behaviour was consistent with cannabis use and anxiety.

HOW THE SAGA UNFOLDED

2014:

May 9: Rizalman follows Tania Billingsley from a shop to her home. After a struggle in the house he is arrested by police down the road.

May 10: Rizalman appears in court and his diplomatic status is considered.

Foreign Minister Murray McCully is informed but Ministry of Foreign Affairs and Trade boss John Allen is left out of the loop.

May 12: An informal discussion between officials from Mfat and the Malaysian High Commission leads to Malaysia concluding that New Zealand "offered" an alternative option for Rizalman to be sent back to Malaysia to face charges.

May 21: Malaysian High Commission tells Mfat it will not waive Rizalman's immunity and asks for all charges to be dropped and all documents to be "sealed".

May 22: Rizalman leaves New Zealand and returns to Malaysia. He is hospitalised for psychiatric evaluation.

June 27: McCully hears for the first time that the Malaysians rejected the request for a waiver. Allen hears about the case for the first time.

June 29: The media reports that a diplomat has claimed immunity and left the country. Malaysian media soon report he was one of their diplomats.

June 30: Prime Minister John Key and McCully are adamant that New Zealand clearly opposed Rizalman leaving and wanted him tried, but on legal advice say they can't name him or the country. Malaysian High Commissioner called in for grilling by Allen; she reveals "ambiguity".

July 1: Fairfax Media lawyers succeed in getting court-ordered name suppression lifted so that Rizalman and the country he represents can be named in New Zealand. McCully releases May 10 and May 21 documents showing New Zealand's unambiguous request for a waiver, and Malaysia's refusal. Hours later McCully concedes informal discussions may have created the "ambiguity" about New Zealand's position. He says Malaysia acted in good faith.

July 2: McCully apologises to Key and Allen apologises to McCully but they both refuse to say if resignations were offered. Allen announces an independent review of Mfat's handling of the event. McCully also reveals that a junior staffer in his office was informed about Malaysia invoking diplomatic immunity but never opened the email.

July 9: A district court judge accepts Billingsley's application for her name suppression to be removed and she speaks to the media.

October: A formal request to extradite Rizalman to New Zealand is made. Rizalman waives the need for a formal extradition and agrees to return.

October 25: Rizalman returns to New Zealand and immediately faces a district court.

2015

November 27: A High Court judge is told the trial does not need to go ahead as Rizalman will plead to one of the charges.

November 30: Rizalman pleads guilty to indecent assault and is remanded for further court hearings.