Rugby Australia is pressing ahead with plans to terminate Israel Folau's contract after the Wallabies full-back was served with a breach notice over his homophobic social media posts.

Folau has been deemed by the union's integrity unit to have committed a "high-level breach of the Professional Players' Code of Conduct", warranting the termination of his employment contract.

The 30-year-old said on his Instagram and Twitter accounts last week that "hell awaits" for "drunks, homosexuals, adulterers, liars, fornicators, thieves, atheists, idolaters."

Castle said: "Following the events of last year, Israel was warned formally and repeatedly about the expectations of him as a player for the Wallabies and NSW Waratahs with regards to social media use and he has failed to meet those obligations.

"It was made clear to him that any social media posts or commentary that is in any way disrespectful to people because of their sexuality will result in disciplinary action.

"All professional rugby players in Australia are bound by the code of conduct and there is a process in place for any disciplinary matter."

Folau has 48 hours to accept the sanction or refer it to a hearing but whatever course of action is taken, he faces an uncertain future in sport.

He has been stood down by the Waratahs and his rugby union career in Australia appears over, while a return to his roots in league has been ruled out by the Australian Rugby League.

Clubs in Europe will also be wary of signing a player who comes with considerable baggage and even Toulon have rejected the possibly of offering an escape route.

The fallout has been felt in the northern hemisphere after England number eight Billy Vunipola offered support for his view on his own Instagram account, resulting in showdown talks with Twickenham.