The Memphis Grizzlies star Ja Morant says he takes "full accountability" for his actions after he was suspended for appearing to hold a gun in a video on social media for a second time.

Morant, 23, appeared to briefly hold up a gun in a car with a friend in a live broadcast on Instagram on Saturday.

He was also suspended for eight games in March after a video showed him holding a gun in a Colorado nightclub.

"I know I've disappointed a lot of people who have supported me," he said.

"This is a journey and I recognise there is more work to do. My words may not mean much right now, but I take full accountability for my actions. I'm committed to continuing to work on myself."

NBA commissioner Adam Silver said the incident is being investigated but he was "assuming the worst".

"We spoke for a long time about not just the consequences that it could have on his career but the safety issues around it. He could have injured, maimed, killed himself or someone else with an act like that," Silver said.

"He has an incredibly huge following. My concern, that I thought he shared with me, that tens of millions of kids globally would see him as having done something that was celebrating in a way, that act of using a firearm in that fashion."

After the incident in March, All-Star guard Morant apologised and said he took "full responsibility" for his actions, as well as undergoing counselling while he was suspended.

Glendale Police Department investigated the nightclub incident but did not find enough evidence to charge anyone for a crime.

Another suspension would see Morant miss the start of the 2023-24 season as the Grizzlies are out of the play-offs after a first round defeat by the Los Angeles Lakers last month.