Israel Folau's sacking has been referred to the Fair Work Ombudsman by a senior senator who suggested Rugby Australia may have broken the law in its treatment of the star fullback.

The devoutly Christian athlete was fired last month after a tribunal found him guilty of a "high-level" breach of the governing body's code of conduct for posting on social media that "hell awaits" gay people.

He has yet to reveal his next step, but could take the divisive case, which has pitted his right to religious expression against restrictions on hate speech, to the courts.

Liberal senator Eric Abetz, a former employment minister, noted that the Fair Work Act and the Australian Human Rights Commission Act ­provided protections against discrimination on the basis of religion.

"Given the widespread coverage of the Folau matter, I believe there is a public interest in fully exploring and considering whether the termination of Mr Folau was actually in violation of the current laws," Abetz, also a devout Christian, said in a statement.

"As a fundamental threshold matter, it is important that we clearly identify if under the ­current law an employer can sack an employee for expressing their religious beliefs on social media outside the workplace. 

"And if not, it will require a careful examination of whether the Act requires amendment and whether the Fair Work Act does not fully protect employees from other forms of discrimination."

Abetz told ABC radio Monday it appeared Rugby Australia was primarily motivated by preventing key sponsors walking away, with airline Qantas among those making clear its displeasure with Folau.

He said he had been "astounded by the number of people who saw Rugby Australia as being very ham-fisted and it would appear motivated by the threat of the sponsor to withdraw money."

Abetz has written to the Fair Work Ombudsman and Australian Human Rights Commission requesting a probe. The ombudsman confirmed the referral and said it would be assessed ahead of a decision on whether to investigate.

Rugby Australia insists the sacking was purely a contract issue, with chairman Cameron Clyne telling ABC Monday that "when he [Folau] pressed send, we had to deal with it."

"It is a serious issue and when people just say it was done because of the sponsors, well obviously sponsors were not happy, but why weren't they happy," he said.