When Rizalman first appeared in court on May 10 he was granted bail and ordered to surrender his passport by 5pm on May 12.
However, in that time police had confirmed with the Ministry of Foreign Affairs and Trade that he was protected under diplomatic immunity.
He returned to his home country that month with his wife and two young children. The Malaysian Government has since volunteered to return him to New Zealand.
It is not clear whether his wife and children will return with him.
Rizalman was expected back a week ago, but Malaysian doctors shelved those plans and ordered further psychiatric testing because he seemed depressed and withdrawn.
It is unclear when he will return, but when he does he will be arrested and taken into custody, according to Stephen Hoadley, associate professor of political studies at Auckland University.
He will then appear in court where his defence counsel can lodge a bail application. They could also make an application for him to be examined by a doctor to see if he is fit to stand trial.
Hoadley said if he is granted bail it is likely Rizalman will be housed at the Malaysian High Commission in Brooklyn or at a hotel with a military escort to mind him. If granted bail, he could face conditions which restrict his movements and forbid him from contacting Billingsley and other witnesses.
It is also unlikely that he will have to surrender his passport, but he would have to prove that he was not a flight risk.
"The Malaysian Government stands behind him and has agreed with the New Zealand Government that he will go to trial, so there will be an element of trust," said Hoadley.
"The danger of him absconding is low because his own government will guide him and make sure that he appears in the right place at the right time."
Rizalman could plead guilty immediately, but if he stands trial, Hoadley said, it is unlikely to be fast-tracked.
"It will be scheduled like all the many, many other cases that are pending and he will just have to get in the queue."
Hoadley said that should he be found guilty, it was highly likely Rizalman would serve whatever sentence was imposed on him in New Zealand, but Malaysia could request to repatriate him.
Peter Williams, QC, said it was possible that an application could be made to have the indictment against him struck out on the basis that media coverage could prejudice his right to a fair trial.
"Such an application is very difficult. It is very seldom that an indictment is struck out on the grounds of there has been a lot of publicity but it would be worth a go."
If that application is declined, Rizalman will stand trial in front of a judge and 12 jurors.
A judge-alone trial was possible but unlikely. "Usually there are two sides to be considered and you need the common sense of a judge," said Williams.
