A former principal accused of molesting students at an ultra-Orthodox Jewish school in Melbourne has had her extradition hearing to Australia delayed.

Malka Leifer fled to Israel just hours after allegations of sexual abuse at the Adass Israel School in Elsternwick first surfaced in 2008, and has been there ever since.

It is understood Ms Leifer could face dozens of charges of indecent assault and rape if she ever returns to Melbourne.

Ms Leifer was first placed under house arrest in Israel last September but nearly a year later there still has not been an initial hearing on her extradition petition.

On Wednesday, her lawyers successfully argued in a Jerusalem court for yet another delay to her case, claiming she is suffering from "psychosis and stress".

Lawyer Yehuda Fried denied dragging the case out.

"I don't accept the word excuses. We are conducting a court procedure," he said outside the court.

"The Israeli law confirms that anyone in a psychotic state cannot be subject to legal proceedings."

He told reporters he was willing to spend years fighting the extradition and would appeal all the way up to the Israeli High court and Minister for Justice if necessary.

Attorney-General George Brandis's department said in statement: "Australia made a request to Israel for Ms Leifer's extradition as she is wanted to face prosecution in Victoria for 74 sexual assault offences.

"As the matter remains before the courts in Israel, it would not be appropriate to comment further."

Activist alleges pressure to keep case quiet

Abuse whistleblower Manny Waks is visiting Israel to bring attention to the issue of child sexual abuse in ultra-Orthodox Jewish communities.

He said he was dismayed the extradition process was taking so long.

Manny Waks blew the whistle on child sexual abuse at his Jewish centre in Melbourne. ( ABC News: Sophie McNeill )

"I've been in contact with a number of complainants in this case and its something I know they are taking in a very difficult way," he said.

Dr Yitzhak Kadman, the executive director of Israeli children's right advocacy organisation National Council for the Child, said he believed Ms Leifer had "very good lawyers".

Dr Kadman said he was worried Israel's powerful ultra-Orthodox community was protecting Ms Leifer and helping to fund her legal case.

"We are aware of how many people tried to create pressure on this case. We think she is well connected. The prosecutor has told us, without getting into details, that there was a lot of pressure not to even release her name," he told the ABC.

"We don't think that Israel should be a country of refuge for suspects of child sex abuse, paedophiles."

In a statement the Israeli ministry of justice told the ABC: "There has been a number of delays to this case caused by the defendant. The Ministry of Justice is doing everything it can to move this case along."

Ms Leifer's case has been adjourned until October 26.