Israel Folau is to be sacked by Rugby Australia following his latest social media posts, leaving the Wallabies facing the prospect of heading to the World Cup in Japan without one of their best players.

RA released a statement on Thursday night, saying it had failed in its attempts to contact the player over the past 24 hours and its intention was to terminate his contract unless he could prove there were “mitigating factors”.

Folau’s playing career in Australia was placed in jeopardy following an Instagram post on Wednesday in which he proclaimed hell awaits “drunks, homosexuals, adulterers, liars, fornicators, thieves, atheists and idolaters”.

It was the second time the NSW Waratahs player had used social media as a platform to disseminate homophobic sentiments, following a series of posts last year, including one which said “God’s plan for gay people was hell”.

Then, RA issued a warning but no further action was taken after Folau threatened to walk away from the game if he felt his fundamentalist Christian beliefs were being compromised.

RA’s integrity unit called a meeting on Wednesday night to discuss the latest posts but subsequent efforts – both from the national governing body and the state body under which the Waratahs play – to contact Folau failed.

“Rugby Australia and the New South Wales Rugby Union have made repeated attempts to contact Israel both directly and via his representatives since 6.30pm on Wednesday, and at this point he has failed to communicate directly with either organisation,” the statement read.

“Whilst Israel is entitled to his religious beliefs, the way in which he has expressed these beliefs is inconsistent with the values of the sport. We want to make it clear that he does not speak for the game with his recent social media posts.

Dear Israel Folau, I’ve already been to hell | Kim Baker Wilson Read more

“Israel has failed to understand that the expectation of him as a Rugby Australia and NSW Waratahs employee is that he cannot share material on social media that condemns, vilifies or discriminates against people on the basis of their sexuality.”

The Wallabies’ major sponsor, Qantas, expressed concern at the posts on Thursday, indicating they welcomed the integrity unit’s investigation. The current deal between the airline and RA is due to expire at the end of the year and negotiations are underway over a renewal.

“Rugby is a sport that continuously works to unite people,” the RA statement said. “We want everyone to feel safe and welcome in our game and no vilification based on race, gender, religion or sexuality is acceptable and no language that isolates, divides or insults people based on any of those factors can be tolerated.

“As a code we have made it clear to Israel formally and repeatedly that any social media posts or commentary that is in any way disrespectful to people because of their sexuality will result in disciplinary action.

“In the absence of compelling mitigating factors, it is our intention to terminate his contract.”

Folau signed a new, multi-million dollar, four-year deal with RA just two months ago. It is unclear whether the new contract contained a specific clause about his use of social media.

RA’s decision potentially leaves Wallabies coach Michael Cheika with a headache just five months out from the start of the World Cup in Japan. Folau, who has won the John Eales medal three times, is Australia’s fourth highest try-scorer of all time and on Saturday he became Super Rugby’s all-time leading try-scorer.

His expected exit from Australian rugby also raises the question of where he goes from here. The code-hopper, who began his career in rugby league and has also had a stint in the AFL, has been linked with a return to the NRL, while a move to European rugby has also been mooted.