By Agence France-Presse
The allegations against Don Burke come amid an ever-widening scandal following the downfall of American movie mogul Harvey Weinstein.
It has seen women across the world revealing their experiences of workplace sexual harassment.
A joint Australian Broadcasting Corporation and Fairfax Media investigation detailed claims from a number of women who worked with Burke, 70, in the late 1980s and 1990s.
They alleged he was a "psychotic bully" and a "sexual predator".
Two former TV researchers claim he groped their breasts, the ABC reported, while a young actress alleged he told her she would have to do an audition topless.
One of the researchers said Burke once showed her a bestiality video and that on another occasion he attempted to remove her clothing and put his hand down her top.
Burke, a long-time fixture on the Australian media scene who is best known for the high-rating gardening show Burke's Backyard which aired for 17 years, called the allegations "baseless".
"The bitter irony is that I have had a life-long opposition to sexism and misogyny," said Burke, who still regularly appears on TV and radio to offer gardening advice.
But the claims received backing from several top TV executives, including former Channel Nine boss Sam Chisholm.
"Don Burke was a disgrace because of his behaviour internally and externally. This precluded him from ever becoming a major star," he told the ABC and Fairfax.
Chisholm's successor at Nine, David Leckie, said Burke's general behaviour was unpleasant.
"I've been trying to think of Harvey Weinstein-type people, and the only one I can ever come up with is Burke," he said.
"He's a horrible, horrible, horrible man. He's a dreadful, dreadful piece of work... he was a really dirty old man."
More bombshell allegations against Australian media personalities could be imminent with journalist Tracey Spicer, a former Channel Ten newsreader, teaming up with Fairfax in an investigation into sexual misconduct across the industry.
The Australian newspaper reported Monday that she had gathered 485 complaints about 65 alleged offenders, but the project had been delayed due to legal issues.