Witness B, whose name and rank is suppressed, on Wednesday told a court that AFP weapons were taken on the trip, during which he says one of Mr Jabbour's relatives shot at kangaroos with what he believed to be Mr Jabbour's police-issue Glock.

Mr Jabbour, who no longer works for the AFP, has pleaded not guilty to unauthorised gun possession and abuse of public office. He is fighting the charges at an ACT Magistrates Court hearing that began on Monday.

The prosecution's case is that Mr Jabbour took his service pistol to a property, which cannot legally be identified, on a trip that was at least partially intended for private hunting on October 3, 2018.

He should not have had the gun in and around that time, according to prosecutor David Jordan, because he was on recreational leave and not performing police duties.

The abuse of public office charge relates to Mr Jabbour allegedly exercising his influence over a more junior colleague and lying to obtain information that a relative subsequently used in a legal studies assignment.

On Wednesday, Witness B told the court arrangements had been made for he and another AFP officer, who must be referred to as Witness C, to accompany Mr Jabbour and his relatives to the property in question.

When they met at an AFP building he had expected Mr Jabbour and his relatives to have brought privately owned weapons to use for hunting, but he said they had not.

"I wasn't very comfortable," Witness B said when asked how he felt about this.

"It wasn't part of the plan."

Witness B said he knew some AFP weapons were being taken on the trip.

But he did not notice until he and Mr Jabbour's relatives split off from the rest of the group that one of the relatives was wearing a holster containing a pistol that appeared to be Mr Jabbour's service weapon.

"I recall going, 'Oh', and identifying that it was a pistol on [the relative's] hip; a Glock model pistol," he said.

Witness B told the court he saw Mr Jabbour's relative fire that gun at kangaroos, while the other relative also discharged AFP weapons at the animals.

He said he had also taken part in the shooting, and estimated that in total "about half a dozen" kangaroos were shot at on the property.

Upon the group's return to a car park at the AFP building, Witness B said he saw the Glock pistol in a box that "went away" with Mr Jabbour and his relatives when they headed home.

The prosecution's case is that Mr Jabbour put the gun back in his office at 4.30am the next morning "to avoid scrutiny" while he was on leave.

Witness B also said Mr Jabbour, unsolicited, had left a $100 gift card on his desk following the trip. He returned the card because it was "very nice, but not required".

Another officer, Witness A, gave evidence that he had helped arrange the October 3, 2018 outing after being directed to do so by a superior.

Witness A said that days after the outing, which he did not attend, Mr Jabbour had "produced four cartons of beer" in appreciation.

Later on Wednesday, Witness C told the court he had seen both of Mr Jabbour's relatives firing AFP weapons on the day in question.

He said he had supervised one of the relatives and estimated they had fired about 80 rounds at kangaroos, pieces of metal and rocks, before both relatives went off with Witness B and fired probably 60 more rounds.

Mr Jabbour's barrister, Ken Archer, told the hearing earlier this week that the defence would argue that the events of October 3, 2018, formed part of Mr Jabbour's AFP duties.

Mr Archer has also said that on the abuse of public office charge, the court would ultimately not be satisfied that Mr Jabbour had acted dishonestly.

Magistrate James Stewart has made a large number of suppression orders covering the hearing, which may continue on Thursday.

Depending on the court's capacity, the matter may need to be adjourned until next year.