Malka Leifer's lawyers say one of the sisters who accused her of sexual assault told "blatant lies", and is a witness who can't be relied upon.
Warning: This story contains details of allegations of sexual abuse.
During closing arguments in Mrs Leifer's County Court sex abuse trial, defence barrister Ian Hill sought to cast doubt over a host of prosecution witnesses, including complainants Dassi Erlich, Nicole Meyer and Elly Sapper.
The sisters have accused the former principal of the Adass Israel School, in Melbourne's inner south-east, of sexually assaulting them between 2003 and 2007, when they were teenagers.
The trio took to the stand for days of evidence and cross-examination, however it played out in a closed court with no members of the public or media present.
Mr Hill said there were more than 400 occasions when the sisters used the words "I don't recall" or "I have no recollections" while giving evidence.
Mrs Leifer, who has watched proceedings from the court dock, has pleaded not guilty to 27 charges against her.
The sisters have been at the County Court complex, but have watched proceedings on a video link from another room.
Alleged victim had 'false imaginations', defence barrister says
Mr Hill took aim at the evidence of Ms Sapper, who failed to disclose aspects of the alleged offending when she spoke to a psychiatrist in 2008.
Later when making statements to police, Ms Sapper added claims Mrs Leifer had penetrated her and used a sex toy during an alleged rape.
"Elly was really just a witness who is not credible, who is not reliable," Mr Hill said.
"Did she get caught out telling blatant lies? The answer is yes."
Mr Hill accused Ms Erlich, the sister who triggered the investigation into Mrs Leifer, of having "false imaginations" of sexual assault and rape.
Mr Hill said Ms Erlich's disclosures to a social worker in Israel in 2008 resulted in remarks being "taken out of all proportion".
"[It] grew like wildfire into a story that was constantly added to and varied over the years," Mr Hill said.
Mr Hill pointed to letters Ms Erlich had written to Mrs Leifer, as proof that the girls were not fearful of the school principal they had built a close personal relationship with.
One of the letters to Mrs Leifer said: "Thank you for all the strength, encouragement and support you've given".
Mr Hill said the defence was at a "disadvantage" because a significant amount of time had passed since the alleged incidents and the case being tried in court.
"There's a loss of opportunity to make any defence other than a simple denial," he said.
Earlier, prosecutor Justin Lewis closed the crown case against Mrs Leifer, saying the former principal abused the sisters in school offices, on camps and at her own home.
Prosecutors told the court the then-teenagers had little understanding about sex during their upbringing, which centred around their ultra-conservative Jewish faith and community.
They claim Mrs Leifer, a revered figure in the school, used her position of authority to silence her alleged victims.
"These sisters had a miserable home life, and so far as the accused was concerned they were ripe for the picking," Mr Lewis said.
Mr Lewis read an excerpt of a diary made by Ms Erlich when she was in Year 11 or Year 12.
He said the entry referenced time spent with Mrs Leifer where "she sat hugging, kissing and stroking me for an hour, begging me to tell her my most innermost thoughts".
Mr Lewis said it was an "extraordinary piece of contemporaneous evidence", that had gone unchallenged by Mrs Leifer's lawyers.
He said if the jury could accept those notes as true, it wouldn't be a stretch to believe Mrs Leifer had committed the sexual offences.
The prosecutor said a cleaner, Mario Toledo, recalled seeing Mrs Leifer and the sisters at the Adass Israel School some Sundays.
"He gave evidence on one occasion he went to clean one particular room, the accused closed the door shut on him and told him not to come in," Mr Lewis said.
The trial continues.
