Old boys from the prestigious Scots College have downplayed the seriousness of sexual assault allegations against three current students in what concerned parents at the school say is a sign of a toxic culture at the elite educator.

There are growing calls for an overhaul of the embattled Bellevue Hill college’s leadership amid criticism of its handling of the alleged sexual assault of a 14-year-old girl and what they say are deep-rooted cultural issues within the school community.

Several parents say the school’s principal, Dr Ian Lambert, should resign immediately as the scandal on Monday deepened with the emergence of messages sent by a prominent former student defending the college and the boys accused of attacking the teenager in an eastern suburbs alley way last month.

Arthur Tzaneros, chief executive of freight giant ACFS Port Logistics, deleted the series of messages sent in an old boys group chat following questions put to him by the Herald. The 13-year-old boy and two 14-year-old boys have been charged with aggravated sexual assault in the company of others, and aggravated sexual touching of another person.

“Before anyone jumps to conclusions, this is no Skaf case,” Tzaneros wrote in what appeared to be a reference to the notorious Sydney brothers Mohammed and Bilal, who, alongside at least 14 other men, raped six schoolgirls over several weeks in 2000.

In other messages sent to more than 100 fellow old boys and seen by the Herald, Tzaneros said the alleged victim was a “willing participant” in the attack and called the students involved “deadshits”.

Tzaneros also said categorisations of the alleged attack as a rape were “fake news”. A member of the group chat, who the Herald has chosen not to identify, challenged Tzaneros, explaining that the boys were charged with aggravated sexual assault, which under NSW law is a charge equivalent to rape.

Other messages sent in the group chat, comprising Scots graduates from 1995, discussed plans for an upcoming heli-ski trip to celebrate several members’ 50th birthdays.

When contacted by the Herald, Tzaneros deleted the messages and said: “I unreservedly apologise for my comments. I deeply regret saying what I said, and for showing a complete lack of sensitivity to the harm of this situation. There is no excuse, and furthermore I am remorseful for my commets [sic].”

Several Scots parents told this masthead the views of some old boys were representative of a long-standing culture at the school that is dismissive of women. The college has been widely criticised for its approach to sexual consent education despite repeated warnings from advocates and concerned mothers.

One parent, who spoke on the condition of anonymity to protect their son’s enrolment, said the school’s reputation as a place that perpetuates toxic masculinity was harmful to all students. They and other parents say Lambert has overseen a culture of fear and he should instead step down immediately. Early this year Lambert announced he will leave the school at the end of 2027.

“So many people are scared to say something. Teachers are scared to say anything because he controls all,” they said.

“Eighteen months is a long time in a child’s education. Our concern is that this creates a holding pattern and that changes which need to happen now could be delayed until new leadership arrives.”

The parent also called for the introduction of a charter of behaviour to govern students’ actions.“Boys are getting too many warnings rather than being expelled,” they said.

“Some teachers are crying because the boys are just not controllable, but that comes back to parenting … we just want our boys to be safe at school.”

Writing for this masthead on Sunday, sexual consent activist and Teach Us Consent founder and chief executive Chanel Contos said Lambert had ignored her attempts to share concerning testimonies from young women allegedly assaulted by hundreds of former Scots students.

Several parents, speaking anonymously because they fear criticism of the school could jeopardise their children’s enrolment, have called for a greater representation of women within the school’s leadership.

Currently, women comprise 39 per cent of staff. There is one woman on the Scots College Council and 10 men.

“That’s not a fair representation of the population,” one parent said.

“There needs to be an increase in female voices in leadership positions.”

Scots, which has refused to answer repeated questions about the accused students’ future at the school and concerns about its culture, said the school was unaware of comments made by old boys.

“The feedback received by the college regarding the handling of this matter has been overwhelmingly positive,” said the school in a statement.

On Monday, a 17-year-old boy was remanded in custody after being arrested alongside several other teenagers whom police say egged one of the Scots students’ homes over the weekend. The student’s parents are generous donors to Scots.