Former constable Zachary Rolfe tendered the certificates during an inquest into the death of Kumanjayi Walker, attempting to prove an ingrained culture of racism within the force.

Mr Rolfe shot Kumanjayi Walker, 19, three times as he resisted being handcuffed while armed with a pair of scissors in Yuendumu, northwest of Alice Springs, on November 9, 2019.

He was acquitted of murder at a five-week trial.

Lawyers spent much of the February inquest session arguing over the legitimacy of "certificates" produced by Mr Rolfe, which aimed to prove Northern Territory Police handed out a racist award at former Christmas parties.

While initially suppressed from publication, Coroner Elisabeth Armitage lifted the suppression on the three certificates on Monday morning.

The first depicts an Aboriginal flag with the Territory Response Group (TRG) logo in the corner with the words "CAUTION for a RAPE... that's all that needs to be said".

The award appears to be from 2013 and the name of the receiving constable is redacted.

The second certificate from 2012 depicts the TRG logo and an image of a police rescue vehicle chasing Usain Bolt.

The words "Runner up SOOTY AWARD, for outstanding lack of excellence in approaching a stronghold" are printed.

The TRG logo is also on the final 2012 award, depicting a naked man lying on his back and a woman wearing revealing clothing.

The words include "award for outstanding lack of excellence in cooking sausages".

NT Chief Minister Eva Lawler said the award was "not acceptable", and Police Minister Brent Potter said police were investigating the matter.

"It's concerning but the police division needs to look at that," he said.

During the inquest, NT Police lawyer Ian Freckleton tendered four statements from senior officers in the Tactical Response Group who rejected the claims, saying no such award existed.

All four statements referenced the award, believed to be the award called out by Mr Rolfe.

They all said the word the award was titled was "made up" and had no connection to Indigenous people.

"This award is presented to people who have displayed an outstanding lack of excellence in the area of personal hygiene or feral behaviour," Superintendent Craig Garland said.

However, the following day Mr Rolfe's lawyers came to court with certificates claiming to be from the recipients of the racist award.

"I believe my lawyers are in possession of a certificate for the award issued in 2013," Mr Rolfe said.

"The officer I just mentioned was a member of, I believe ... the canine unit in Darwin.

"He has passed on some certificates, one that he alleges he received in 2013 on invitation to this annual party."

Mr Rolfe requested the identity of the officer not be released, but wrote it on a piece of paper for the lawyers to see.

Dr Freckleton made a successful application to prevent the media publishing the images of the award until investigations took place, though descriptions were said to be "offensive" and include the Aboriginal flag.

Another unnamed former police officer emailed the coroner during the inquest, allegedly corroborating Mr Rolfe's story about the racist police award.

In February, NT Police Commissioner Michael Murphy said police were now conducting an internal investigation with ICAC about the awards.

Mr Murphy admitted the award was racist, whether the certificates were verified or not, but said NT Police does not have a systemic racism problem.

- with Australian Associated Press