Australian Boomers coach Brian Goorjian says NBA star Josh Giddey has his “full support” as the 21-year-old deals with an NBA investigation over allegations of improper behaviour.

Giddey, who played with the Boomers at the World Cup this year and looms as key to Australia’s medal chances at the 2024 Paris Olympics, is being investigated following an allegation in a since-deleted anonymous social media post.

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The NBA has confirmed Giddey, who took to the court for the Oklahoma City Thunder on Sunday, was being investigated with the young Australian making no comment when asked about it pre-game by local media.

Goorjian said the issue was “out of my wheelhouse” but has sent a message to Giddey expressing his support.

The veteran coach said he’s travelling to the United States next month to meet with Giddey and other Boomers playing in the NBA and expected to be made more aware of the situation.

“It’s really out of my wheelhouse,” Goorjian said on the Gold Coast on Monday.

“All I’ve done is messaged him and let him know the support is there.

“I am going to go over in early December and see him face-to-face.

“I just want to let him know right now he’s got our full support.”

Oklahoma City have not stood Giddey down after the emergence of images and video last week and then more across the weekend.

Coach Mark Daigneault declared the NBA’s investigation wouldn’t impact Giddey’s availability.

“Just with the information that we have at this point, that’s the decision that we’ve made, it’s really not even a decision to be honest with you,” he said.

The Thunder coach was then asked whether he anticipated the ongoing league investigation could result in Giddey missing games in the future, however he refused to be drawn, simply stating: “It’s obviously a league matter at this point, so ball is in their court on that.”

Giddey was cheered by the OKC crowd on Sunday and didn’t seem affected by the off-court situation, playing a solid game in the Thunder’s 127-123 loss to Philadelphia.

The Thunder are not scheduled to play again until Friday.

Daigneault’s comments come after the NBA launched an investigation into the allegations against Giddey that emerged on social media last Thursday.

“We are looking into it,” NBA spokesman Mike Bass confirmed in a statement to news.com.au on Saturday.

Giddey meanwhile refused to comment on the allegations against him during a team media event on Saturday, stating: “I understand the question obviously, but there’s no further comment right now.”

The Boomers star is currently in the third year of a four-year $41m rookie contract with the Thunder - but could command significantly more in his next contract given the way he has burst onto the NBA scene, utilising his six-foot-eight frame and incredible passing skills.

Allegations against Giddey emerged last Thursday when pictures and videos were posted to social media featuring the Australian Boomers star with a young woman.

One of the images is of a shirtless Giddey standing behind the woman.

There are videos which feature Giddey supposedly talking to the girl’s brother, in which he says: “I’m here with your beautiful sister.

“Good luck for your season. I hear you’re going to Sacramento soon for a game so best of luck. We’re going to come up and watch you take care of business.”

In another video, where she appears to be standing in the background outside a nightclub, Giddey says: “What’s up my man? We’re at the front of the club, me and my girl, about to head back to mine.”

The legal age to attend a nightclub in the United States is 21.