Radio hosts Kyle Sandilands and Jackie O will not be prosecuted for contempt of court over on-air comments made during mushroom murderer Erin Patterson’s trial.

A man with a grey beard and black cap and a blonde woman resting her hand on his shoulder smile in a radio studio.

Kyle Sandilands and Jackie O have a long history of breaching radio broadcasting rules. (Facebook: The Kyle and Jackie O Show)

Sandilands took to the airwaves on KIIS FM and said “lock that bitch up” during a news segment about the case on June 16.

It was the same day prosecutors began closing arguments in the high-profile trial.

“Is this big lump still getting around, this big lump … miserable looking thing,” he said on the Kyle and Jackie O show.

“My question is how strong is her case?” his co-host asked.

“Not strong, not strong for her,” Sandilands replied.

Erin Patterson with glasses on and head down gets into a van outside court

Erin Patterson was eventually sentenced to life in prison for the murders of Don and Gail Patterson and Heather Wilkinson. (AAP Image: Joel Carrett)

Later in the segment, Sandilands again accused Patterson of being guilty.

“The rest of us already know … come on bro, you can tell by looking at her, lock that bitch up,” he said.

“Takes too long, these courts should be in and out, decided and moved on.”

Patterson, who was eventually found guilty of murdering three relatives and trying to poison another with a toxic beef Wellington, had maintained her innocence at the trial.

Prosecutors had also previously accused her of trying to kill her husband, Simon, but discontinued those charges.

The radio hosts’ comments drew the ire of the Patterson trial judge, Christopher Beale, who referred the matter to the Director of Public Prosecutions to consider contempt of court charges.

A Mamamia Out Loud podcast episode and a public presentation made by Dr Rachel Toles titled The Psychology of Serial Killers were also referred to the director.

On Wednesday afternoon, a spokesperson for the Office of Public Prosecutions confirmed no charges would be laid.

“It has been determined that in all the circumstances none of the incidents had a clear tendency, as a matter of practical reality, to prejudice the fair trial of Ms Patterson on the charges against her,” the spokesperson said.

“It is considered that the required elements of contempt could not be proved beyond reasonable doubt, and there are no reasonable prospects of conviction for the referred incidents.”

While jury trials are ongoing, media outlets are required to report only facts before the court to safeguard jurors from outside information.

Media outlets or journalists found guilty of sub judice contempt risk large fines or potential jail time, and in worst-case scenarios, trials have been abandoned due to problematic reporting.

Radio hosts told to ‘engage their brains’

On June 16, Justice Beale condemned the comments made on the Kyle and Jackie O Show when jury members were out of the room.

“I have read a transcript of that commentary. I encourage all commentators to engage their brains before they open their mouths, as they may otherwise land themselves and their organisations in hot water,” he said.

On June 5, Justice Beale also addressed the Mamamia podcast episode.

“The discussion was full of highly prejudicial expressions of opinion. I won’t repeat them here. After being directed to remove the podcast, it has been taken down,” he said.

“I remind media and podcasters that ignorance of the law is no excuse.”

Kyle and Jackie O have a long history of controversial on-air segments and breaches of the commercial radio code of practice.

In October, they were found to have breached decency rules while airing segments about urination and genitals, a s.. game, and pornography websites.