Adelaide comedian JooYung Roberts has spoken publicly about his alleged indecent assault by ABC host Tom Ballard, saying the decision to identify himself was spurred by the global #MeToo movement.

Mr Roberts alleged the incident occurred four years ago in a hotel room in Adelaide after a comedy gig, where he said Mr Ballard kissed him and sexually assaulted him.

Mr Ballard, the host of ABC show Tonightly with Tom Ballard, has denied the allegations "in the strongest terms possible".

Mr Roberts told the ABC he was encouraged to make the allegations publicly known through the media because of the success of the #MeToo movement.

"I would say that up until now speaking up in public would not have been worth it… but with the #MeToo movement people are much more willing to engage with the issue of sexual assault happening," Mr Roberts said.

He said he went to the police several days after the alleged incident, however was rebuffed as he "hadn't said no".

"He hadn't gone outside the confines of the law," Mr Roberts said earlier in a statement on his Facebook page.

"And there wasn't really anything that could be done so I left the station safe in that knowledge.

"I decided to live my life."

He said he again sought to report the alleged incident to the police in December, but police advised him an investigation would not proceed because of the poor likelihood of a prosecution.

South Australia Police said they had received a report in December about offences alleged to have occurred in June 2014.

"Investigation into the report is complete and the matter finalised," a police spokeswoman said.

"There will be no further action or comment by police."

#MeToo didn't come for three and a half years

In the post, Mr Roberts said his mental health suffered in the following years after the alleged incident, and he ignored the signs he needed help.

"Me Too didn't come for three and a half years and in that time my mental health just got worse and worse," he said.

"I didn't seek therapy. I didn't let people in the Australian comedy community know about what had happened.

"It was a secret that had to be kept, desperately, for the sake of my career."

Mr Roberts said he used his post to provide advice to survivors, as well as point out challenges to sexual assault victims from coming forward and reporting the crimes.

He blamed the reason very few allegations had been made public in Australia on the nation's defamation laws.

The Adelaide comedian urged victims of sexual assault to seek professional help for trauma and not wait until they hit "rock bottom".

"We need real systems put in place to prevent sexual assault from happening and make the path to recovery easier for victims to undertake," he said.

"We need to change not just the way we view consent but also the way we silence victims.

"Our defamation laws are stopping countless Australians from seeking the justice they deserve."

In a statement provided over the weekend, Mr Ballard said he had "absolutely no idea [Mr Roberts] believed it wasn't consensual until six months ago".

"His version of that experience as described on social media is simply not what happened," he said.

The ABC said it would not make further comment on the matter.

For help or support for suicide or mental health issues, call Lifeline on 13 11 14 or BeyondBlue on 1300 224 636.