The 55-year-old had been charged with seven counts of indecent assault and six of common law assault against four women during a run of the musical in Australia.

Melbourne magistrate Belinda Wallington on Tuesday dismissed all 13 charges.

But she wanted it known the four complainants "were brave and honest witnesses".

She rejected McLachlan's suggestions the women colluded against him.

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The magistrate noted laws around the standard of proof required for consent had changed since the time of the allegations.

Current standards, that an accused's belief in consent must have been reasonable, are not retrospective and may have changed the outcome of the charges, Ms Wallington said.

Among the allegations were that McLachlan tickled a woman's thigh from behind while onstage.

Prosecutors argued this amounted to indecent assault or, failing that, assault.

Melbourne Magistrates Court was told McLachlan played tricks on the cast to make them laugh.

In her decision, Ms Wallington said the Gold Logie-winning actor, who filmed TV series Doctor Blake Mysteries in Ballarat, seems to have thought touching his co-star this way was funny.

But she could not exclude the possibility that an "egotistical self-entitled sense of humour led the accused to genuinely think that (the woman) was consenting to his actions".

McLachlan was also accused of tracing his finger around the outline of another woman's vagina while they performed a "bedroom" scene.

Prosecutors said this wasn't part of McLachlan's role as Dr Frank-N-Furter.

The court was told he'd previously made jokes and the woman's "little slit" being visible through her costume.

Ms Wallington concluded McLachlan stopped touching the woman when he became aware she didn't consent, and dismissed that charge of indecent assault.

McLachlan has always strenuously denied all the allegations against him.

His legal team took aim at his accusers' motivations for coming forward, the clothes they wore, poses they struck in photos and the way they interacted with cast members during the highly sexualised production.

Ms Wallington was perturbed that McLachlan's lawyers, led by Stuart Littlemore QC, seemed unfamiliar with rules prohibiting inappropriate questioning.

"I was not assisted by the lines of questioning ... that called into question the reputations of the complainants, sexual or otherwise, (or) the poses they struck," she said.

McLachlan gave evidence that always been "energised and enthusiastic and over the top in the workplace".

He did not appear in person for Tuesday's decision and instead tuned in remotely from Sydney.

Following the decision, he told reporters he'd maintained "a dignified and respectful silence for the past almost three years" and put his trust in the law.

"We aren't going to speak in any detail today. We will certainly do so in the immediate new year. As you can imagine, we have a lot to say," McLachlan said.

-Australian Associated Press