Racist texts to be probed after NT cop's Supreme Court bid fails

Constable Zachary Rolfe refused to answer questions during the inquest into the death of teenager Kumanjayi Walker, but the ruling means he must return.

Constable Zachary Rolfe will return to the inquest into the death of the Warlpiri teenager he shot and killed, Kumanjayi Walker. Source: AAP

A Northern Territory police officer can be forced to answer a coroner's questions about the night he shot a Warlpiri teenager dead.

Constable Zachary Rolfe shot Kumanjayi Walker, 19, three times during a bungled outback arrest in Yuendumu, northwest of Alice Springs, on November 9, 2019.

An inquest into the teenager's death has been repeatedly disrupted by a legal stoush about whether the 31-year-old officer has the legal right to refuse to provide evidence to the coroner and the court's ability to compel him to do so.

Coroner Elisabeth Armitage previously determined that witnesses cannot decline to answer questions by invoking the penalty privilege, which Const Rolfe did when he appeared at the inquest in November.

She said penalty privilege was extinguished by the NT Coroner's Act Section 38, which allows the coroner to compel a witness to give evidence that could incriminate them and for the provision of an immunity certificate from prosecution after doing so.

Const Rolfe's legal team disagreed and took the matter to the Supreme Court for judicial review last month.

It said the certificate would not protect him from internal police disciplinary proceedings potentially stemming from his evidence, and Section 38 does not abolish penalty privilege and it remains available to him as a common law right.

But Justice Judith Kelly disagreed. In a judgment released on Thursday she said "penalty privilege is not available in a coronial inquest under the Act".

The effect of the ruling is that Judge Armitage should now be able to compel Const Rolfe to answer uncomfortable questions about racist text messages that the inquest was told he sent.

He is also likely to be asked about the night he killed Mr Walker and his alleged misuse of police body-worn cameras, excessive use of force and falsified NT police recruitment application.

All told, there are 14 categories of evidence Const Rolfe could be forced to answer questions about, including nine incidents related to investigations over his use of force on the job.

A jury found him not guilty in March of murdering Mr Walker, causing outrage in his grieving community, along with hopes that the inquest would provide answers where the trial had failed.

The inquest continues on February 27.