A former principal of an Orthodox Jewish girls' school in Melbourne has been arrested in Israel over alleged sexual assault offences in Victoria.

Australian police have made an extradition request for Malka Leifer.

The mother of eight was sacked as principal at the Adass Israel School in Elsternwick in 2008 after being accused of inappropriate conduct with students.

She returned to Israel 24 hours after the allegations were publicly revealed.

Ms Leifer denied any wrongdoing.

The Federal Attorney-General's office confirmed the extradition in a statement.

"Malka Leifer has been arrested in Israel in response to an extradition request made by Australia," the spokesperson said.

"Ms Leifer is wanted to face prosecution in Victoria for alleged sexual assault offences.

"As the matter is now before the court in Israel, it would not be appropriate to comment further."