The NBA has ended its investigation into Oklahoma City Thunder guard Josh Giddey over an alleged inappropriate relationship with an underage girl, ESPN has reported.

Police in Newport Beach, California, announced in January they would not pursue charges, saying they were “unable to corroborate any criminal activity related to Mr Giddey”.

Now the NBA has brought its own investigation to a close, according to Thursday’s report.

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The 21-year-old, who is bound for the Olympics with Australia’s Boomers, was not suspended during the police inquiry.

The Melburnian has not commented on the allegations and continued to play for the Thunder during their run to the Western Conference semi-finals.

The top seed’s campaign was ended by the Dallas Mavericks, Giddey’s offence stuttering as he was used sparingly and eventually made to start from the bench for the first time in his three-season career.

He did score 21 points – hitting three late triples – in a series-sealing sweep of New Orleans in the first round, and had enjoyed a run of strong form in April while star pair Shai Gilgeous-Alexander and Jalen Williams were injured.

That is the Giddey the Boomers will hope to call on in Paris from July, where the 2021 NBL rookie of the year is set to pilot the charge for the bronze medallists from the Tokyo Games.

Giddey, the Thunder’s sixth pick in the 2021 draft, was left out of Australia’s Olympic side that ear as the Boomers reached the podium for the first time at a major tournament.

Patty Mills was the focal point, scoring 42 points in Australia’s defeat of Slovenia in the bronze-medal game.

Mills, along with Joe Ingles, is readying for a fifth Games campaign but coach Brian Goorjian plans to run a new-look side’s offence through Giddey in France.

“With Giddey, instead of moving side-to-side (with the ball) like the Europeans, more north and south,” he told AAP.

“We’ll try to get him downhill, attacking early on the clock.”

Goorjian has publicly supported Giddey since the investigation into him opened late last year.

“He is a young man and (we) are part of his development. We have a responsibility, and I do, to develop him as a human being,” he told AAP.

Australia’s men will play World Cup bronze medallists Canada, led by Gilgeous-Alexander, as well as qualifiers from two July tournaments that could include heavyweights Greece, Slovenia or Spain in a stacked Games pool.

“Our pool, my first look was, ‘Oh my god’,” Goorjian said.

“Then it’s that deep breath of, ‘Bring it on, you’re at the Olympics’.”

– with AAP