Media mogul Lachlan Murdoch is taking defamation action against the Australian operators of Crikey news.

The Federal Court on Tuesday listed an application brought by Mr Murdoch against Private Media, its managing editor Peter Fray and political correspondent Bernard Keane.

A spokesperson for Mr Murdoch confirmed the defamation proceedings but refused to make further comment.

The much-anticipated legal action follows an opinion piece published by Crikey on June 29 about the ‘‘sorry state of US politics and the January 6 insurrection’’ where protesters stormed Congress.

The article twice mentioned the Murdoch family name.

‘‘You responded through your lawyers with a series of letters in which you accused us of defaming you personally in that story,’’ Private Media chairman Eric Beecher said in a letter to Mr Murdoch posted on social media.

‘‘We want to defend those allegations in court.’’

The matter is yet to be assigned a court hearing date.

In a statement made after the court’s confirmation of the writ, Private Media CEO Will Hayward said Crikey stands by its story.

‘‘We look forward to defending our independent public interest journalism in court,’’ Mr Hayward wrote.

‘‘We are determined to fight for the integrity and importance of diverse independent media in Australian democracy.’’

In a highly unusual step, the local publication took out an ad in The New York Times on Monday calling on the US-based Mr Murdoch to make good on legal threats over an article about the US Capitol riots and News Corporation’s coverage of former president Donald Trump.

Lawyers for Mr Murdoch claimed in late June that Crikey defamed him by implying he “conspired” to overturn the 2020 presidential election, demanding a retraction and apology from the outlet’s editorial staffers.

But in a surprising twist, half-a-dozen legal letters detailing the claims were made public on Monday by Crikey, revealing correspondence between lawyers for its publisher Private Media and Mr Murdoch’s lawyer.

-with AAP