Gary Neiwand, 57, pleaded guilty to harassing a woman last year - 15 years after first being jailed for stalking a former girlfriend and four other people.
The relationship was over when Neiwand began bombarding his latest victim with text messages.
He also threatened to send pictures and messages to her best friend's husband, and later followed through on the threat, the woman told Melbourne Magistrates Court on Thursday.
Neiwand, whose five-page criminal record includes two previous stints in prison, copped a conviction and $1000 fine for his latest criminal actions but was warned if he continued to play by his own rules he'd be headed back to jail.
"What makes this so serious is you understand the punishment for putting yourself above the law," Magistrate Abigail Burchill told Neiwand.
"You've gone to jail not once but twice, and there is something fundamentally wrong with your thinking (for you) to keep doing this."
The community needs to be protected from Neiwand, who has repeatedly shown the court he is a person who makes up his own rules, she said, questioning how the court could have confidence in a person with that pattern of behaviour.
In court the victim said she had repeatedly asked Neiwand to stop contacting her, and had blocked his mobile number and social media accounts.
She would sit in the dark at home pretending not to be there in case he showed up at her house.
"My whole body would shake in fear," she said.
The woman said Neiwand's actions had led to her going back on anti-anxiety medication, and affected her relationships in such a way that she now expects to be alone.
Neiwand's lawyer said he has been seeing a psychiatrist regularly and has experienced significant benefit from acceptance and commitment therapy.
He competed in four Olympic Games for Australia, taking home two silver and two bronze medals.
Neiwand also took home gold medals at three World Championships and Commonwealth Games.
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