Israel Folau's Australian rugby union career appears over, after a three-person panel ordered that the Wallabies star's four-year contract be terminated as punishment for his breach of the players' code of conduct.

Key points: Folau was stood down by Rugby Australia last month in the wake of his social media posts

Folau was stood down by Rugby Australia last month in the wake of his social media posts His professional sporting career is now in limbo

His professional sporting career is now in limbo His chances of moving back to the NRL were ruled out last month

The panel, which this month ruled that Folau was guilty of a "high-level breach" of the players' code over his controversial Instagram posts, including one proclaiming hell awaits "drunks, homosexuals, adulterers, liars, fornicators, thieves, atheists and idolaters", decided to rip up the 30-year-old's four-year, $4 million contract.

Rugby Australia (RA) chief executive Raelene Castle said the decision had not been directly communicated to Folau.

"Rugby Australia did not choose to be in this situation, but Rugby Australia's position remains that Israel, through his actions, left us with no choice but to pursue the course of action resulting in today's outcome," Castle said.

"People need to feel safe and welcomed in the game, regardless of their race, background or sexuality."

Castle confirmed Folau has 72 hours to appeal the decision, but would not comment on reports he plans to take the case to the Supreme Court.

She said the Wallabies star knew his social media posts would have wider implications "when he pressed that button".

"This is a decision that will change the landscape for sport across Australia and perhaps internationally," she said.

"It will be landmark, it will be important, and it is a big decision.

"He is a very important player in our game and he has been for a long period of time and we wanted to make sure we took the time to get it right."

Folau maintains he is doing his 'duty as a Christian'

Folau released a statement on Friday evening saying he was "deeply saddened" by the decision, and that he was considering his options.

"It has been a privilege and an honour to represent Australia and my home state of New South Wales, playing the game I love," Folau said.

"As Australians, we are born with certain rights, including the right to freedom of religion and the right to freedom of expression.

Folau has 72 hours to appeal against the decision. ( AAP: Dan Himbrechts )

"The Christian faith has always been a part of my life and I believe it is my duty as a Christian to share God's word.

"Upholding my religious beliefs should not prevent my ability to work or play for my club and country."

Folau thanked his family, particularly wife Maria, "for her love and encouragement to stay true to our beliefs".

The former Wallaby also thanked those who defended his right to express his beliefs, despite not sharing them.

"We have been humbled by the support we have received from family, friends, players, fans and the wider community," he said.

"Thank you also to those who have spoken out in my defence, some of whom do not share my beliefs but have defended my right to express them."

Folau's football future in limbo

Folau, who played 73 Tests for the Wallabies, fronted a three-person tribunal at the beginning of May, comprising of chair John West, Rugby Australia's representative, Kate Eastman, and the Rugby Union Players' Association-appointed John Boultbee.

The 30-year-old was stood down by RA last month in the wake of his social media posts.

He was then issued with a code of conduct breach notice recommending his four-year $4 million contract be terminated, which he decided to challenge.

Wallaby great Tom Horan said that should Folau successfully appeal against the decision, the former Waratah still has a lot of work to do to add to his 73 Test caps.

"He'd have to explain himself to teammates and win the dressing room back again," Horan told the ABC.

"It'll probably come down to how much he wants to play in the gold jersey again."

With the rugby World Cup taking place in Japan in September, the likelihood of seeing Folau board the plane appears even less likely.

His presence will be missed: he's the equal third-highest Wallabies try scorer of all time.

The Wallabies came close to claiming the World Cup in 2015, but without Israel Folau they face an even tougher task. ( Reuters: Toby Melville )

"It's probably more sad for a player like Israel not be able to play in a rugby World Cup again," Horan said.

"And it's sad for the game of [Australian] rugby, where the game has struggled a little bit over the last two or three years and there's an opportunity to play great rugby in the World Cup and potentially go close to winning the World Cup.

"It's a blow for the World Cup."

Folau's professional sporting career is now in limbo, with a move to European or Japanese club rugby union hardly guaranteed.

A move back to the NRL, where his professional career began back in 2007, was ruled out last month when the league said the Australia and Queensland rugby league representative did not pass the code's "inclusiveness culture".

Castle said she could not foresee Folau playing for New South Wales or Australia again "while the post remains up and he is unapologetic for his actions".

'We will continue to support them'

Rugby Australia may face a potential backlash from Polynesian players, after Wallabies prop Taniela Tupou claimed all Pacific Islanders "might as well just be sacked" owing to their religious beliefs in the wake of the Folau controversy.

Tupou earlier this month expressed his support for the under-fire Folau on Facebook, but Castle said she was confident players understood that everyone has a right to their own religious beliefs.

"As long as they continue to express them in a respectful way we will continue to support them," she said.

"The expectation is that everybody is entitled to their own differing beliefs and views on all manner of subjects.

"But if you are going to express them as an employee of an organisation, when you have signed a contract that clearly sets out the expectations of the values of that code, you must abide by that contract and if you don't, it is a breach of contract and your contract could be terminated."

Castle said the league had many players who quoted the Bible on their social media platforms, noting Rugby Australia was "completely supportive of that".