Together with Americans Michael Andrew and Tom Shields, Hungary's three-time Olympic gold medallist has hired California law firm Farella Braun & Martel, SwimSwam have reported.

The International Swimming League (ISL) have filed a separate lawsuit for the same reason.

The lawsuits involve FINA’s moves to block the 2018 Energy for Swim meet that was supposed to be hosted in Italy on December 20 and 21 and feature some of the world's top swimmers, including Hosszú, Britain's Adam Peaty and Chad le Clos.

"My passion has always been to push swimming in the direction where swimmers are partners of the governing body, not just muppets," Hosszú said. 

"ISL takes swimmers seriously, not like FINA."

Hosszu and Andrew are due to swim at the Short Course World Championships next week in Hangzhou in China - an event organised by FINA. 

The lawsuit is similar to the one filed against the International Skating Union in 2017, where a judge ruled that their moves to block skaters from competing in non-authorised competitions were in breach of European Union antitrust laws, except that this one is being filed in the US.

The lawsuit claims violations of the Sherman Antitrust Act of 1890, which forbids organisations from engaging in anti-competitive behavior. 

The Sherman Act resulted in the breakup of Standard Oil and AT&T, among other organisations. 

Attorneys for the plaintiffs also claim tortious interference with contractual relations or prospective economic relations, for collusion to unreasonably restrict competition, and for monopoly. 

The lawsuits seek injunctive relief and monetary damages for the named plaintiffs and for all class members, which could include dozens of professional swimmers from around the world who signed contracts. 

The class, if accepted, would not be limited to just Americans, even though the suit is filed in the US.

According to the release, the suit was only undertaken after FINA demanded a $50 million (£39 million/€44 million) fee to approve ISL events.

"On behalf of elite swimmers around the world, the plaintiffs charge FINA with unlawfully restraining competition in the market for top-tier international swimming competitions," a release from Farella Braun & Martel said. 

"Their lawsuit follows FINA’s crackdown against a two-day competition that a new professional league planned to sponsor in Turin, Italy, in late December 2018. 

"Organisers were forced to cancel that meet after FINA said it would ban from the Olympics any swimmer who swam in it. 

"As result, swimmers lost the chance to compete for more prize money and were blocked from earning appearance fees.

"The popularity of competitive swimming has soared over the last decade. 

"Its athletes believe a professional league that will compensate its best athletes and better reward them for a lifetime’s worth of hard training and sacrifice is long overdue."

The ISL, bankrolled by Ukrainian oligarch Konstantin Grigorishin, was responsible for coordinating the Turin event offering $2.1 million (£1.7 million/€1.8 million) in prize money that FINA blocked, and it has plans to roll out a series of matches in 2019 featuring approximately 300 of the world’s best swimmers.

"Governing bodies and commercial enterprise co-exist in other sports and even work together for the betterment of the sport," ISL chief executive Ali Khan said.

"But FINA’s priorities just are not aligned with those of the swimmers, and as a result the sport has not been allowed to evolve with the times.

"The ISL deserves a chance to offer swimmers more opportunity to compete and earn a living, and the swimmers deserve not to be shackled to FINA’s whim. 

"And the laws here and in Europe require that ISL has that chance.”

According to the lawsuit, FINA earned about $118 million (£93 million/€104 million) in gross revenues from all aquatics events in 2016 and 2017, yet paid only 12.5 per cent of that amount to athletes in the form of prize money.

"Very few select swimmers make a living swimming, while FINA is making a killing," Andrew, a gold medallist in the 100 metres medley at the 2016 FINA World Championships Short Course, said. 

"FINA’s main consideration is not for swimmers. 

"FINA set our sport back into the dark ages by blocking ISL’s request. 

"They can co-exist."

To read the full Class Action Complaint click here. 

insidethegames has asked FINA for a comment. 

More follows