DISGRACED former Auburn deputy mayor Salim Mehajer has joined forces with his solicitor sister threatening to launch Australia’s biggest defamation case.

The plan to outdo Rebel Wilson — who recently won Australia’s biggest defamation payout of $4.5 million over media giant Bauer — was outlined in a letter to a journalist sent today, Fairfax Media reports.

Bauer is appealing Wilson’s record payday.

But Salim plans to seek plenty more than that.

Signed by Zenah Osman, the sister of the embattled property developer, the letter sent via email says Salim and “related entities” will launch defamation proceedings seeking $103 million against a number of media outlets.

“Our client will be commencing legal action against, not limited to, Channel Seven, A Current Affair, The Daily Telegraph, which will be in our view Australia’s Largest Case of Defamation,” Ms Osman said in the letter, which is on a MLG Solicitors letterhead and Fairfax says was sent at 2.15am Saturday.

It seems Fairfax will escape Salim’s defamation aim: it was reportedly chosen as the recipient of the email because “at this stage” Salim isn’t bringing proceedings against it.

“Being in the media spot light [sic] is tough and brutal. One must be very patient and enduring,” Mr Mehajer says in a statement at the bottom of the letter.

“I let the media throw in all the punches for the past twenty months and watched my case build just like a business deal. I think now though, it has reached its peak and its [sic] time I commenced legal proceedings. All proceeds will be donated to charity.”

The letter is signed off by Ms Osman as “principle” [sic] solicitor.

Salim’s legal threat, which apparently will be filed next week, will be the latest in a string of legal battles he is fighting on a number of fronts.

It caps an action-packed fortnight in which Salim was injured in a car crash, delaying court hearings over assault charges for allegedly robbing and assaulting a taxi driver outside Sydney’s Star Casino in April. That case was adjourned until January.

On Wednesday, Salim was in hot water again when a secret recording containing vile abuse was leaked.

The life and times of Salim Mehajer The life and times of Salim Mehajer

Mehajer, 31, has been accused of making the abusive phone call to a man at Queen Street Customs, a prestige car hire and repairs shop in Revesby, NSW, a few weeks ago.

“You f***ing son of a b****, let’s meet up,” a man can be heard saying in the leaked audio obtained by Seven News.

“You’re a Shia dog, you motherf***er watch if I don’t do it to ya, you son of a b****!

“Your mum’s going to get f***in’ raped today you f***in’ dog! I’m f***in’ coming to your house now you son of a bitch, you f***in’ Shia dog! I’m going to f***in’ rape ya!”

The caller, alleged to be Mehajer, can also be heard on the recording telling the other man that “all the boys wanted to grab you”.