Israel Folau has commenced court proceedings against Rugby Australia (RA) and his former team the Waratahs.

Folau, a devout Christian, had his contract terminated by RA and the Waratahs for a "high-level breach" after he posted "hell awaits... drunks, homosexuals, adulterers, liars, fornicators, thieves, atheists and idolaters" on Instagram.

RA and Folau in June failed to reach a settlement over the full-back's sacking, with the 30-year-old having set up a GoFundMe page, which was subsequently shut down, to raise money for his legal challenge.

A second fund-raising page – through the Australian Christian Lobby – was paused after receiving donations totalling more than two million Australian dollars.

And, as expected, Folau has now opened legal proceedings against his former employers.

"Unfortunately, our conciliation before the Fair Work Commission did not resolve the matters between us and I have been left with no choice but to commence court action," Folau said in a statement.

"I have been blessed to have received the support of tens of thousands of Australians throughout my journey, and I want to say thank you to everyone who has offered their prayers and support.

"It has meant so much to Maria and me over the last few months and gives us strength for the road ahead."

Following the failure to reach an agreement with Folau in June, RA and NSW Rugby Union expressed their regret.

"Rugby Australia and NSW Rugby Union are incredibly disappointed that [the] Fair Work conciliation has been unsuccessful and did not reach a resolution," a statement read.

"We remain confident in our processes and will continue to do what is required to defend the values that underpin our game."