Australian billionaire Clive Palmer’s spokesman has denied claims by far-right political strategist Steve Bannon that he was behind Palmer’s controversial $60m advertising strategy at the 2019 federal election.

The text conversation purporting to be between Bannon and an unidentified person – who appears to be convicted sex offender Jeffrey Epstein – was among a tranche of documents released by the US Department of Justice in connection with Epstein.

One version of the conversation shows Bannon talking to a person whose identity has been redacted. A separate file, containing the same conversation, appears to show the other participant is an email account that has been linked to Epstein.

Bannon, a Donald Trump loyalist and promoter of misinformation who ran the US president’s 2016 election campaign, said in the messages sent two days after the 2019 Australian election: “I had Clive Palmer do the $60 million anti china and climate change ads.”

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The claim purportedly made by Bannon is untested and was dismissed as “bullshit” by Palmer’s spokesperson on Sunday.

The 2019 federal election was marked by a significant rise in online misinformation and an unprecedented ad blitz by Palmer’s United Australia party.

On election night, Palmer said he pivoted his strategy in the final weeks of the campaign “to polarise the electorate” and damage Labor’s chances of winning.

Scott Morrison’s Coalition government was returned despite polls consistently pointing to a Labor victory.

In the conversation days after the election, the account linked to Epstein comments on the failure of published polls to predict the result, and compares the Australian election to “your last go round”.

The account purporting to be Bannon responds with the claim that he “had” Palmer run advertisements about China and climate change.

In an interview with the Sydney Morning Herald during the campaign – about a week before Palmer pivoted his advertising spend – Bannon described the campaign as dull, and that he was surprised at the lack of reference to China.

“There should be a really intense debate about this,” he said.

“They are trying to hold the election on national security, and it should be tied to China.

“The insurgent parties should be generating the intensity, and they’re not.”

During the campaign, Palmer ran a two-minute advertisement attacking Labor that made claims that “communist China” was attempting “a clandestine takeover of our country”.

Labor’s election review cited the “bizarre” claims in concluding that Palmer’s advertising had “a significant negative effect on [Labor leader] Bill Shorten’s popularity and on Labor’s primary vote”.

“Following a preference deal with the Coalition, Clive Palmer dovetailed his $70 million advertising spend with the Liberal Party’s in the final two weeks of the campaign, moving his attack to Bill Shorten as ‘Shifty Shorten’ and, in Western Australia, to a bizarre claim the McGowan Government sold an airport to China for $1.00,” the election review said.

“Palmer’s advertising blitz strongly amplified the Coalition’s anti-Labor message to economically insecure, low-income voters. In focus groups of soft voters, Palmer was described in the most derogatory terms, helping explain the poor vote he and his party received, but his blitz against Shorten took its toll on Shorten’s leadership standing.”

Palmer’s media spokesperson, Andrew Crook, responded to Bannon’s claims of involvement via text message on Sunday.

“This is made up. Just bullshit,” he said.

Bannon has been contacted for comment.