Australia's most-capped rugby union international is accused of orchestrating a takeover of sportswear and equipment business PTP Fitness.

Former managing director and co-founder Alexander Goldberg claims he was unlawfully dismissed while on carer's leave by fellow co-founder Matthew Dixon and Gregan.

"The criteria for acting in bad faith ... there are many in this case. They acted dishonestly; they exercised power for an ulterior motive or collateral advantage," Mr Goldberg's barrister, Robert Stitt QC, said in his opening address to the Federal Court on Tuesday.

Mr Goldberg was on a salary of $300,000 when sacked in June 2019.

Gregan, a former Wallabies captain, and Dixon, a former NSW Waratahs player married to Mr Goldberg's sister, say they took action after finding their business partner was registering company trademarks in his own name.

"On any view, that is a breach of the shareholders' agreement," barrister Robert Newlinds SC said.

"He'd been specifically told to stop and he kept doing it."

PTP was valued between $11 million and $13.2 million by one consultant in late 2020.

Dixon, 52, and Goldberg, 41, both own 40 per cent while the remaining share is held by Gregan and his wife.

Gregan, 48, was at one stage paid an endorsement fee of about $20,000 a year but, like Dixon, is now on a salary of almost $500,000, the court was told.

The former rugby players deny the oppression and unlawful dismissal claims, and instead want court findings that Mr Goldberg breached director duties.

Mr Newlinds said a settlement offer made on Monday was rejected and his clients wanted the chance to counter serious accusations aired in public in recent weeks.

"My clients have ... kept their powder dry and this is their opportunity to put their side of the story," he said.

"(They) are anxious to have the opportunity in the public arena to vindicate their names."

PTP was built with Dixon's capital and Mr Goldberg's ideas, Mr Newlinds said.

"(Mr Goldberg) hates the fact he isn't running the show, he hates the fact he's a minority shareholder," Mr Newlinds said.

There was "nothing inappropriate" about Gregan and Dixon's remuneration, which was increased after independent advice and soaring profits.

"The company is entitled to pay its executives market rate," he said.

Mr Goldberg has also taken issue with the withholding of dividends since 2018.

Mr Stitt said his client was the subject of a "commercial attack" and claims of intellectual property theft and misconduct were a "red herring".

Conversations between Dixon and Gregan could infer the pair "embarked on a strategy that had no regard to the law", he said.

"Eventually I'll put that to Gregan," Mr Stitt said.

He later stated there was no allegation the conspiracy was criminal.

The hearing continues.

Australian Associated Press