Israel Folau attended a Rugby Australia hearing on Saturday over his anti-LGBT social media posts in April.
A three-member panel will weigh whether Folau, a fundamentalist Christian, breached RA's code of conduct for writing a post on social media that said hell awaits "drunks, homosexuals, adulterers" and others.
RA and Folau's Super Rugby team, the New South Wales Waratahs, have already publicly committed to terminating Folau's contract, so the closed hearing has been written off by some observers as a formality.
The governing body will argue that the 73-test full-back's commentary is a form of vilification, at odds with its inclusion policy and a 2014 pledge to remove homophobia and other forms of discrimination from the game.
RA will also argue that Folau is a repeat offender, having caused similar controversy with a social media post last year that said gay people would go to "hell" unless they repent.
Yet despite being hauled before RA and Waratahs' executives for "discussions" about the post last year, Folau was given no sanction.