The judge presiding over the murder trial of Northern Territory police officer Zachary Rolfe says he has "no idea" when it will go ahead after the prosecution won a High Court bid to have the trial, which was set to begin on Monday, halted.
The High Court ruled the three-week trial be stayed after the prosecution applied for special leave to appeal a decision handed down by the NT Supreme Court in relation to the defences available to Mr Rolfe.
The special leave application will be made in the High Court on September 10.
Mr Rolfe, 30, the son of a prominent Canberra family, has pleaded not guilty to murdering Kumanjayi Walker, 19, in November 2019.
He has also pleaded not guilty to two alternative charges of manslaughter and reckless conduct causing death.
Both parties appeared in the Darwin Supreme Court on Monday, shortly after the decision was handed down, when Justice Dean Mildren discharged the jury.
Justice Mildren told jurors he had "no idea" when the trial would be relisted for, now that the stay had been granted.
"There's no guarantee as to whether the High Court will deal with the matter straight away or they may reserve their decision and consider it later," Justice Mildren said.
"We have no idea at the moment when this trial may be able to proceed."
A number of Mr Walker's family members had travelled from Central Australia for the trial and were present in court in Darwin.
Speaking outside court, Mr Walker's cousin Samara Fernandez said the family was very happy with the High Court decision to stay the trial.
"We're just happy to let the judicial system play out for now," she said.
Crown prosecutor Philip Strickland SC, also speaking outside court, said the High Court ruled that his appeal application had "some reasonable prospects".
He said he was hopeful the trial could take place this year.
Mr Strickland said it was the Crown's argument that the decision to allow Rolfe's legal team to use three separate defences before the jury, including the immunity clause in the NT Police Administration Act, was wrong.
He said it was not consistent with the criminal code, which required a police officer's actions to be reasonable for immunity to apply, and that the criminal code's reasonableness provision was designed to protect the public from the excessive use of force.
The interpretation of the act is central to Mr Rolfe's trial.
High Court Justice Jacqueline Gleeson noted in her judgement, handed down on Monday morning, it was "arguable" that the prosecution's interpretation of the immunity clause was correct.
"It is arguable that s148B applies only to the functions that are expressly conferred on members of the Police Force of the Northern Territory, such as the power of arrest in s124 of the Act, and not to functions that may be identified by reference to the core functions stated in s 5(2), such as a function to protect the life of a particular person (other than the deceased)," the judgement reads.
The trial has previously been postponed twice by the COVID-19 pandemic.
The matter will return to the Darwin Supreme Court for a mention on September 13.
Mr Rolfe will remain on bail and will not be required to attend the mention.