Crikey hired a marketing company to capitalise on a legal threat from Lachlan Murdoch in order to drive subscriptions, the co-chair of News Corporation has alleged in the federal court.

Murdoch launched defamation proceedings in August against the independent news site over an article published in June that named the Murdoch family as an “unindicted co-conspirator” in the US Capitol attack. The trial has been set down for March 2023 but the parties are in dispute over pretrial matters.

One of the matters heard by justice Michael Wigney in a brief hearing was an allegation by the Murdoch team that a marketing campaign, run by brand strategists Populares, undermines the public interest defence on which Crikey publisher Private Media was relying.

In response to a concerns letter from Murdoch in June, Crikey initially agreed to take down the article but after failing to reach agreement it was reinstated on 15 August.

Sue Chrysanthou SC, for Murdoch, said she intends to show that republication of the article was not for public interest reasons but for a marketing campaign.

She said Populares produced a “significant report” titled “Lachlan Murdoch Campaign” about how “a dispute with my client could be marketed for the purposes of attracting new readers and gaining subscriptions”.

“The purpose of the re-posting was not for the public interest, it was for the media campaign,” she said.

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In his statement of claim in August Murdoch alleged that the placement of a New York Times advertisement inviting him to sue Crikey over the alleged defamation was “seeking to humiliate” the executive chair and chief executive of Fox Corporation.

Chrysanthou said social media was “the modern-day grapevine” and alleged Crikey had paid for some posts about her client “to be promoted and advertised”.

She sought orders for Crikey to provide further information in response to questions because the submitted outlines of information did not address anything after the 29 June publication of the article by Crikey’s politics editor, Bernard Keane.

Wigney said the request for written answers to about 180 questions, including sub-questions, could delay proceedings and he repeatedly asked Chrysanthou: “Do you want this to go to trial in March?”

“I would withdraw those interrogatories you can cross-examine them,” he said.

Private Media’s lawyer, Clarissa Amato, said Chrysanthou’s request would result in a “a catastrophic waste of time and money”.

“Some of those may be things simply left out of the discovery list by accident … there are other requests that are effectively new categories of documents,” Amato said.

Chrysanthou said the social media posts about her client had spread “like a virus”, and she would call a social media expert to give evidence explaining the reach.

“We want the expert to address that issue, and the effect of promoting particular posts and how that then causes those posts to appear in different people’s feeds,” Chrysanthou said.

She said the expert would be asked to explain a few essential posts, relevant to claims of serious harm from the publication.

Murdoch is seeking damages because through the publication and republication of the article he alleges he “has been gravely injured in his character, his personal reputation and his professional reputation as a business person and company director, and has suffered and will continue to suffer substantial hurt, distress and embarrassment”.

The parties will return to court on Thursday.