Lachlan Older, 23, now of Western Australia, hand-delivered the pamphlets to properties around central and residential Warrnambool in December last year.

The papers wrongly accused a doctor of illegally supplying medication in exchange for sexual favours from minors.

Older pleaded guilty in Warrnambool Magistrates Court on Monday to a rarely heard charge of behaving in an insulting manner in a public place.

A charge of stalking was withdrawn.

He was convicted and fined $1200.

Magistrate Franz Holzer said the offending would have had a "significant, profound and perhaps long-standing impact" on the victim, their reputation and sense of ease in a relatively small community.

"The behaviour is obscene, vile and hurtful," he said. "(Their) reputation has been tarnished and that is something that is troubling me very much indeed."

Stephanie Mawby, representing Older, told the court her client was not the principal offender and his motivation was to "notify the community of something that he believed to be true".

She said Older's mother, Charmaine West, had provided the incorrect information which he "took on face value".

"His mother has directed him to drive to Warrnambool and told him there was a sexual predator in the area," Ms Mawby said.

"And with that he assisted in handing out the pamphlets. He should have made inquiries given the significant allegation made."

Ms Mawby said Older wanted to please his mother, who he had "quite a toxic" relationship with.

The court heard the doctor received a call from their practice manager last year saying someone had distributed photos of them with "derogatory conversation".

The medical centre where the doctor was employed at received a number of phone calls from concerned patients, and an anonymous report was made to the Medical Board of Australia.

The court heard in the hours after the images were discovered, West sent emails to a family member of the doctor saying she was sorry to hear what had happened and that it would be hard for a "professional to recover from a scandal like this".

The family member did not respond.

The court heard West later sent a birthday card to that same person and her hand-writing was linked to the distributed flyers.

Her son was identified through CCTV footage from Warrnambool train station on the day he delivered the pamphlets with his then-girlfriend.

The pair spoke to a V/Line bus driver outside the train station on December 7.

When Older said he was handing out the flyers, the bus driver took note of his registration and the vehicle he was driving was later found to be registered to West.

A subsequent police raid at property in Bannockburn, near Geelong, located a large bundle of the flyers as well as clothes worn by Older and his then-girlfriend in the CCTV footage.

Ms Mawby said West was sentenced in Geelong Magistrates Court to a 12-month community correction order.

She said the charge against Older's ex-girlfriend was still being negotiated in Geelong Magistrates Court.

IN OTHER NEWS

Our journalists work hard to provide local, up-to-date news to the community. This is how you can access our trusted content: