News Ltd media reported on Wednesday that NRL clubs had made enquiries about Folau returning to the 13-man code after his four-year Rugby Australia contract was torn up last month for a controversial post on social media.
Beattie said the NRL would not sanction the 30-year-old's return.
"We are an inclusive game with respect for all. Israel has social media posts online that go against what our game stands for," Beattie told Australia Associated Press.
"As it stands, he will not be considered for registration. What Israel chooses to do in relation to his social media posts and his faith is a matter for him."
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Folau, a fundamentalist Christian, was sacked by Rugby Australia and his Super Rugby club New South Wales Waratahs for posting on social media that hell awaits "drunks, homosexuals, adulterers" and other groups.
The post remains on his Instagram account and has over 70,000 "likes".
Dual international Folau started his professional sporting career in the NRL, playing 91 games for the Melbourne Storm and Brisbane Broncos.
After a less successful two-year stint in Australian Rules football, Folau switched to union in 2013 and scored 37 tries in 73 tests, while claiming the John Eales medal as the country's best player a record three times.
After being found guilty of breaching Rugby Australia's code of conduct with his social media post, Folau declined a chance to appeal his termination, saying he had "no confidence" in the governing body's judicial process.
Local media have speculated he will fight his termination in court after taking further legal advice in the wake of the decision.
The Australian Financial Review reported on Wednesday that Folau had engaged law firm Macpherson Kelley to handle his case.
“We believe Rugby Australia and the Waratahs have acted unfairly and unlawfully in their treatment of Israel,” the firm's head of employment George Haros said.
“Israel has several options available to him at this point, and we are considering his next steps.”
(Reporting by Ian Ransom; Editing by Sudipto Ganguly/Peter Rutherford)
