Brett Brown has resigned as the head coach of the Australian Boomers ahead of the rescheduled Tokyo Olympics.

He has informed Basketball Australia that a change in his personal circumstances over recent months has left him unable to commit to the men's national team Olympic campaign.

As a result, he has stepped down immediately.

"This was a difficult decision which did not come easy," Brown said of his decision.

"The uncertainties around the direction of my professional future unfortunately mean that I cannot commit to the time and preparation that this job deserves and requires. The difficulties around traveling internationally with my family during the pandemic have also contributed to my decision."

The Philadelphia 76ers fired Brown in August, a day after his seventh season with the team ended in a first-round postseason sweep.

Brown had worked with the Australian men's team in the 1990s and early 2000s and again from 2009 to 2012 before joining the 76ers. He was hired again in November last year on a short-term basis for the Olympic assignment after Andrej Lemanis quit, and had been expected to do work with the Boomers during the NBA break.

But the Tokyo Olympics were postponed to 2021 because of the COVID-19 pandemic, and the NBA season was also seriously interrupted.

Further complicating the arrangement, a later than usual start to the next NBA season might mean that some players and coaches will miss the Olympics.

"Basketball Australia is naturally disappointed that Brett is no longer able to commit to being the Boomers' head coach for the delayed Tokyo Olympics, but we fully understand Brett's situation, and appreciate his candidness when informing us of the decision," said Basketball Australia CEO Jerril Rechter.

"The COVID-19 pandemic is creating a challenging environment for all sports in which to operate. The Tokyo Olympics is an important event for Basketball Australia and our male athletes, as collectively we believe the Boomers have an excellent opportunity to claim their first-ever Olympic medal.

"Basketball Australia will commence recruitment for this position in the coming period, with details of the process to be released in due course."

The Associated Press contributed to this report.