The National Basketball League has erupted into civil war, with two groups of clubs clashing over governance and financial matters, and the direction the competition is taking under wealthy businessman Larry Kestelman.

This masthead can reveal a seismic split between agitators South East Melbourne Phoenix, Perth Wildcats and Illawarra Hawks, and the remaining seven franchises, which the league says are backing Kestelman – the Sydney Kings, which has former NBA stars Luc Longley and Andrew Bogut as minority owners, Melbourne United, Brisbane Bullets, New Zealand Breakers, Adelaide 36ers, Cairns Taipans, and the Tasmania JackJumpers, the latter of which Kestelman remains a minority owner until 2027.

As reported by this masthead, the Phoenix, Wildcats and Hawks have taken legal action against Kestelman and the league, questioned governance and financial matters, established an independent Professional Basketball Club Owners Association, forced mediation over travel and flight costs with the two parties still no closer to a resolution, and called for the release of a secret Basketball Australia report which the league says cleared Kestelman of any wrongdoing.

But the seven club owners have fired back, releasing a united statement on Saturday.

“We are united in our vision to ensure the game of basketball in Australia and New Zealand continues to thrive. We will always push for full transparency throughout the sport and all bodies associated with it,” the statement said.

“This new ‘owners association’ has been created by three owners who have a long-standing legal fight with the league. This group is not representatives of the majority of NBL club owners, and their views do not reflect the views of the other seven owners.

“Creating a separate, independent group to advocate for clubs is not necessary. We already have strong, open and collaborative lines of communication with the league.

“There is a regular owners forum with NBL management that all clubs are invited to attend and can contribute items for discussion.”

The seven-month BA investigation was led by former solicitor-general Justin Gleeson SC. But the Phoenix, Wildcats and Hawks maintain the report provided more specific detail, and want BA to release it, and for Kestelman to waive confidentiality. BA says the report is confidential under its national integrity framework, and the NBL says it does not have the power to release the report.

The Phoenix are majority owned by US-based businessman Romie Chaudhari, the Perth Wildcats are owned by multi-millionaire Mark Arena, while the Illawarra Hawks are led by Jared Novelly, a US-based billionaire, Crest Sports and Entertainment chief, and now Donald Trump’s US ambassador to New Zealand.

A day after NBL chief executive Dave Stevenson took a swipe at the dissident franchise owners, declaring the league will continue to work with those who are “aligned in purpose”, the seven clubs backed his assertion.

The seven clubs insist the league has “never been in a stronger position in relation to its value, audience, and fandom”, and say the league has experienced almost 100 per cent broadcast growth over the past three years.

They also argue that since Kestelman bought the league in 2015, attendance has doubled, with more than one million fans attending across each of the past three seasons, while the league is attracting elite imports and playing talent.

United, one of the glamour franchises, was recently valued at $50 million.

“The NBL have made significant changes regarding governance which they have been communicating clearly and often with NBL club owners, including adding highly respected board members in Len Komoroski – former CEO Rock Entertainment Group – Cleveland Cavaliers - and Professor Graeme Samuel AC, the former chair of the ACCC,” the statement from the seven clubs said.

“We acknowledge the challenges of moving from startup to a scale up, and we as club owners are committed to continuing to work with the league to grow the game in Australia and New Zealand for our players and fans.”

A spokesman for the Professional Basketball Club Owners Association said the new entity looked forward to working with league chiefs.

“The Club Owners Association welcomes the willingness of the NBL to work collaboratively with clubs, owners and the owners’ association. A head of the Club Owners Association will be in place soon, we look forward to positive collaboration,” the spokesman said.

Stevenson made it clear where the league’s priorities are.

“The NBL will continue investing its time, energy and resources in working with the vast majority of clubs that are aligned in purpose and committed to the collective success of the competition,” he said.

“Our focus remains firmly on growing the game for everyone involved. That means making decisions that strengthen the league as a whole, create greater opportunities for all clubs, and continue delivering a world-class competition for our fans, players and partners.”