The man, who Fairfax Media has chosen to not to name, made his comments on an internet blog allegedly associated with prominent figures from Melbourne's Orthodox Jewish community.

Fairfax Media has confirmed the man, who is a member of one of the St Kilda Yeshivah centre's leading families and is presently overseas, is wanted for questioning by police in connection to an alleged sexual assault in the 1990s.

The man's extreme views were posted in 2011 and were made as part of a discussion on an ancient Jewish rule known as Mesirah, under which a Jew is forbidden from informing on a fellow Jew.

The case highlights the tension in some parts of the Jewish community, in which some people hold conflicting views about the appropriateness of reporting another Jewish person to authorities.

In some cases, those who do assist police can be ostracised and given the derogatory label of "moser", which means an informer.

The issue is likely to be examined by the royal commission into child sexual abuse next week, with public hearings in Melbourne to examine how Orthodox Jewish communities handled reported cases of abuse.

"Some dangerous nonsense has been posted in comments, and it appears that at least one commenter imagines that mesiroh is some sort of peccadillo that can be winked at," the man posted in 2011.

"It is practical halocho [Jewish law] that a mosser may be killed, here and now in 21st century Australia, by anyone who is able to get away with it."

Fairfax Media earlier this week revealed tape recording and emails demonstrating the pressure placed on some Jewish sex abuse victims not to assist police.

Outspoken Melbourne victims' rights campaigner Manny Waks said on Thursday that the Royal Commission hearings would expose the extent of intimidation of several victims. He also hoped they would be a catalyst for a change in attitudes within the Orthodox Jewish community.

"It's critical that the public and the Jewish community are fully informed of the victim intimidation that has gone on in recent years. Sadly it seems to be the norm within the Orthodox segment of our community, both in Australia and globally. I believe that a combination of pressure from both external and internal forces will be the catalyst for change," Mr Waks said.

"The reality is, there are many other victims out there, and no doubt some of them have been intimidated into silence by virtue of what they have observed is happening within our community. Rabbis and other leaders are sending mixed messages. In some cases it is due to ignorance and in others it's to protect Jewish institutions and the reputation of our community."

Since 2010, the Rabbinical Council of Victoria has repeatedly and publicly encouraged members of the Jewish community to report sex offences to police and has ruled that such actions will not breach Jewish law.

However, in 2008, the council chose to conduct an in-house inquiry into alleged inappropriate touching and financial transgressions committed by a prominent member of Melbourne's Orthodox community.

Despite having up to 20 people come forward with allegations against the man, as reported by the Australian Jewish News newspaper in 2008, the council stated at the time that police would be contacted only if its inquiry determined crimes had been committed.

Honorary Victoria Police chaplain and head of the Organisation of Rabbis of Australasia Rabbi Meir Shlomo Kluwgant led the Victorian rabbinical council at the time of the 2008 inquiry.

Rabbi Kluwgant said this week that "there were rumours circulating within our community with regard to inappropriate behaviour by a trusted official in our community".

Rabbi Kluwgant said the extent of the rumoured inappropriate behaviour was not known and, as such, the inquiry was set up and people were encouraged to make confidential disclosures.

Asked why the council did not immediately alert police to the alleged inappropriate behaviour, Rabbi Kluwgant said he personally advised police of information brought to the council at the conclusion of its inquiry.