In a case of man bites dog, an elite private school in Melbourne is suing a parent because it claims she defamed the institution on a bogus internet website.

Disgruntled mother “Julia Barkly” created the website that purports to be an official school site in a revenge attack after her son was expelled from the Anglican school, Southwood Boys Grammar.

In its statement of claim, to be heard by the Federal Court in June, Southwood says “Ms Barkly’s” website alleges that principal Jenny Collins “values only those students who have marketing potential for school promotions or a parent on the school board”.

“Ms Barkly”, a lawyer who uses a pseudonym to hide her own identity, sued the school after her son was expelled. The school settled the case out of court and agreed to pay her AUS$10,000 (pound;6,000), but without admitting any liability.

The school claims it acted following 15 incidents of “bullying, harassment, wilful misconduct and unacceptable behaviour”.

Southwood charges fees of up to AUS$20,000 (pound;12,200) a year and says it only took legal action as a last resort, after it became aware of the website and “Ms Barkly” refused to shut it down.

Australia’s 1,000 private schools now enrol more than a third of the nation’s school-age children and 40 per cent of those in the final secondary years. Despite many schools charging high fees, the private sector receives almost pound;6 billion a year in funding from state and federal governments.

Now run as tightly-controlled, highly-competitive businesses, private schools are prepared to take parents to court for non-payment of fees. But the Southwood case is believed to be a first for a school to sue for internet defamation.

Use of the web by angry parents or their offspring to defame schools and teachers appears to be on the rise. Students at schools in Melbourne and Perth were caught and punished recently for using the Facebook website to attack their teachers.