Constable Zachary Rolfe, 29, is accused of murdering Kumanjayi Walker, 19, who was shot three times in the remote community of Yuendumu in November 2019.

Rolfe was supposed to stand trial in the NT Supreme Court next Monday after his trial was twice postponed by the COVID-19 pandemic.

It could now be further delayed after the Crown announced its intention to seek leave from the High Court to appeal a recent legal decision related to Rolfe's defence.

The prosecutors will return to court on Thursday to apply for a stay of the jury trial pending the outcome of the High Court application, a court spokesman said.

A full bench of the NT Supreme Court on Friday found Rolfe's legal team could employ three separate defences in the trial, including that he should not be held criminally liable because he was acting in "good faith" when performing his job as a police officer.

Rolfe is charged with murder and the alternative counts of manslaughter and engaging in a violent act causing death.

He has pleaded not guilty to all charges.

His trial was previously postponed in July when the Crown's interstate prosecution team found themselves unable to travel to the NT from virus-ravaged Sydney.

It was later rescheduled to Wednesday when prosecutor Philip Strickland SC agreed to fly to Darwin to undertake two weeks' quarantine at Howard Springs.

But it was further postponed when parts of the Top End were plunged into a three-day lockdown on Monday after an infected US man travelled from Sydney to Darwin.

When the trial goes ahead it is expected to run for three weeks in Darwin, which is about 1500 kilometres north of Yuendumu.

Australian Associated Press