Donald Trump has shared doctored images on social media showing Taylor Swift and her fans support his presidential campaign, in an apparent effort to tap into the pop singer's mega star power in the US election.

Swift has not yet publicly thrown her weight behind any presidential candidate in the November 5 election, but she backed President Joe Biden in 2020 and has previously been critical of Trump.

On Sunday, Trump shared screenshots of posts with manipulated images – including some that an expert said appeared to be AI-generated – suggesting that the pop star and her fans, popularly known as Swifties, support his campaign.

In his Truth Social post, which includes a poster of Swift clad in an Uncle Sam outfit and instructing her fans to vote for Trump, the former president wrote: "I accept!"

That poster is either "AI generated or just classically manipulated," said Hany Farid, a digital forensics expert at the University of California, Berkeley.

The post also includes photos of women wearing shirts with the slogan "Swifties for Trump," some of which Farid said had the "tell-tale signs of being AI generated."

What makes the mash-up "particularly devious" is that is a combination of real and fake imagery, with at least one photo of a woman wearing such a shirt looking legitimate, Farid said.

There was no immediate comment from Swift about the post by Trump, who separately shared on Truth Social a video of a supporter voicing the dubious claim that "Swifties were rallying for Trump."

Swift's soaring popularity and sway over her fans could make her support valuable in the upcoming presidential election.

Both Republicans and Democrats have long wanted to count on her support, but the megastar has been largely reticent about her political leanings.

In a demonstration of her star power, when Swift encouraged her fans to register to vote last fall, directing them to the nonpartisan nonprofit Vote.org, her plea had an immediate impact.

Following her message, the institution said it recorded more than 35,000 new registrations, 23 percent more than last year and the most since 2020.

Swift's feelers into politics have been heavily scrutinised, making her a ripe target for political misinformation and right-wing conspiracy theories.

Her reserve led many critics to speculate Swift was a closet Republican, until 2018, when she broke both her silence and the internet by endorsing the Democratic opponent of far-right US Senator Marsha Blackburn in Tennessee.

She has since spoken out in particular for the legal right to an abortion and LGBTQ+ rights.

In recent weeks, intense speculation has swirled on social media that Swift will endorse Democratic nominee Kamala Harris in the November election.

The megastar has not commented publicly, but that has not stopped legions of fans to form a group called "Swifties for Kamala," attracting tens of thousands of followers on platforms such as Instagram and X, formerly Twitter. (AFP)