A star of Australian hit television show Prisoner: Cell Block H, the women’s jailhouse drama that screened globally throughout the 1980s, has been found guilty of sexually abusing a 13-year-old girl 31 years ago, a court official said.

Maggie Kirkpatrick, 74, who played prison warden Joan ‘The Freak’ Ferguson for nearly 400 episodes, was found guilty of two counts of indecent assault and one count of gross indecency on a person under 16 by the Melbourne Magistrates Court, the official said.

Kirkpatrick had fought the charges, but the magistrate said he believed the victim was a truthful witness after her account of being molested at the actress’s home in 1984. Kirkpatrick met the teenager through a colleague who was a patient at the same psychiatric facility as the victim.

The conviction makes Kirkpatrick Australia’s third television star to be found guilty of child molestation in the 1980s.

Last year Robert Hughes, the star of sitcom Hey Dad! was imprisoned for at least six years, after being found guilty of sexually assaulting minors including on the set of the show. The same year, Rolf Harris was sentenced to almost six years for indecent assault of four young girls from 1968 to 1986.

In June, an Australian government inquiry into child abuse said it was inviting witnesses from the entertainment industry to testify, widening its scope beyond religious organisations.

Kirkpatrick, who also appeared in 18 episodes of beachside drama Home and Away in separate stints in 1991 and 2004, is unlikely to face prison because prosecutors agreed she could receive a non-custodial sentence.

She will be assessed for a community corrections order and return to court today.

Australian law protects the identity of the victim in sexual complaint cases.