Supporters of an orthodox Jewish school principal accused of sexually assaulting her students have funded a public relations and legal campaign to prevent her being extradited from Israel to face trial in Australia.

Key points: Ex-educator faces 74 counts of sexual assault

Ex-educator faces 74 counts of sexual assault Campaigners lobbying for Israel to oppose the extradition order

Campaigners lobbying for Israel to oppose the extradition order Claims she is suffering from mental illness and is unfit for trial

The former principal of the Adass Jewish school in Melbourne, Malka Leifer, is fighting attempts to bring her back to Australia to face 74 counts of sexual assault.

She left Melbourne 10 years ago when the allegations against her surfaced and this week was granted leave not to attend her extradition hearing in Jerusalem on mental health grounds.

Ms Leifer's legal team said she was catatonic and unfit for trial. ( Supplied )

'Rotten Almond' campaign attacks Justice Minister

Israeli newspaper Yediot Ahronot revealed details of the campaign to oppose the extradition, reporting that it included videos attacking the justice system and Israel's Justice Minister Ayelet Shaked.

The minister's surname, Shaked, means "almond" in Hebrew, and the public relations firm reportedly called its campaign "Rotten Almond".

The plan also included filing a lawsuit against the psychiatrists treating Ms Leifer, hiring another psychiatrist to list failings with the medical evidence, and publishing sympathetic videos about the supposedly harsh treatment of "granny Malka Leifer".

Ms Leifer's family issued a statement saying her treatment by the justice system had been "inconceivable" and was more like Turkey or Iran than Israel.

Ms Leifer is being held in prison until a decision is made on her extradition. ( ABC News: Sophie McNeill )

They said they were raising important questions about the case that should bother the Israeli public.

There has been intense resistance to the extradition and hostility towards Ms Leifer's alleged victims from sections of the orthodox Jewish community in Israel and Australia.

Public relations consultant Ronen Tzur defended his involvement in the campaign, telling Israeli radio station Maariv that reports the campaign was well-funded were false.

"We're talking about a poor family, they hardly have money, they saved few hundred shekels, so they can reveal this issue," Mr Tzur said.

"This woman is a grandmother, she has eight children, she has been locked up in jail for eight months, and it's not her fault.

"No one even cross-examined her."

The Minister told Israel's Army Radio she would not be intimidated.

"This case has dragged on for four years in court because the defendant was claiming she isn't fit to face trial, arguing that she needs psychiatric treatment," she said.

"I'm saying if the court decides to give the order to extradite her, I will sign that order.

"No campaign here will scare me."

Malka Leifer's alleged victims, sisters Dassi Erlich, Elly Sapper and Nicole Mayer, were in Israel this week for the extradition hearing.

Ms Leifer with the class of Ms Mayer. ( Supplied )

Dassi Erlich says she's saddened by the news of the campaign, but not surprised.

"We are not entirely shocked, this was kind of expected," she said.

"We knew that Leifer's team would go to any lengths and fall to any level to make sure [the extradition] doesn't happen."

Psychiatric reports contradict catatonic claims

Ms Leifer had been on house arrest, living in an isolated orthodox Jewish settlement in the West Bank, telling the court she was catatonic and unable to live a normal life due to severe mental illness.

But she was arrested for obstruction of justice in February 2018 after private investigators filmed her shopping, socialising and interacting normally, in blatant contrast to the medical evidence her team had submitted.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 10 seconds 1 m 10 s The undercover operation to bring alleged paedophile principal Malka Leifer to justice

Government psychiatric reports also said she was fit to face trial in Australia.

But the extensive delays and the court's treatment of Ms Leifer have shocked and disappointed Dassi Erlich and her sisters.

"It's been an incredibly intense two weeks in Israel and going to court yesterday, not being able to face Leifer, which was one of the reasons we came here, having a closed court and they just seem to be able to continue playing these dirty games and getting away with it," she said.

Israeli authorities arrested Ms Leifer in 2014, but the extradition proceedings have been stuck in the courts for the last four years, and are likely to run well into next year.

After that, Ms Leifer will still have the right to appeal any extradition order.