Donald Trump has been indicted by a grand jury after a probe into hush money paid to a porn star, becoming the first former or current US leader to face criminal charges even as he makes another run for the White House, the New York Times reports.

The newspaper reported on Friday (AEDT) that Mr Trump is expected surrender to authorities at some point to be fingerprinted, photographed and even potentially handcuffed as the legal process kicked off by the indictment rolls on.

The charges he faces, arising from an investigation led by Democratic Manhattan District Attorney Alvin Bragg, could reshape the 2024 US presidential race.

Mr Trump previously said he would continue campaigning for the Republican Party’s nomination if charged with a crime.

On Friday, he responded to news of the indictment with a lengthy statement describing it as part of a “Witch-hunt to destroy the ‘make America great again. movement.”

Mr Trump, 76, sought re-election in 2020 but was defeated by Democrat Joe Biden. He has since consistently claimed he lost to President Biden due to widespread voting fraud and has called the investigation that led to his indictment a “political witch hunt”.

“The Democrats have lied, cheated and stolen in their obsession with trying to ‘get Trump,’ but now they’ve done the unthinkable – indicting a completely innocent person in an act of blatant election Interference,” he said.

“Never before in our nation’s history has this been done. The Democrats have cheated countless times over the decades, including spying on my campaign, but weaponising our justice system to punish a political opponent, who just so happens to be a president of the United States and by far the leading Republican candidate for president, has never happened before. Ever.”

District Attorney Bragg’s office last year won the criminal conviction of the businessman-turned-politician’s real estate company.

A grand jury convened by District Attorney Bragg in January began hearing evidence about Mr Trump’s role in the payment to Ms Daniels days before the 2016 presidential election that he ended up winning.

Ms Daniels, a well-known adult film actress and director whose real name is Stephanie Clifford, has said she received the money in exchange for keeping silent about a sexual encounter she had with Mr Trump in 2006.

The former president’s personal lawyer Michael Cohen has said Mr Trump directed hush payments to Ms Daniels and to a second woman, former Playboy model Karen McDougal, who also said she had a sexual relationship with him.

Mr Trump has denied having affairs with either woman.

As the indictment reports emerged on Friday, Mr Cohen released a statement.

“For the first time in our country’s history, a president, current or former, of the United States, has been indicted. I take no pride in issuing this statement and wish to also remind everyone of the presumption of innocence as provided by the due process clause,” he said.

“However, I do take solace in validating the adage that no one is above the law, not even a former president.”

Federal prosecutors examined the Ms Daniels payoff in 2018, leading to a prison sentence for Mr Cohen but no charges against Mr Trump.

No former or sitting US president has ever faced criminal charges. Mr Trump also faces two criminal investigations by a special counsel appointed by US Attorney General Merrick Garland and one by a local prosecutor in Georgia.

Mr Trump, a divisive figure in US politics with support particularly among white blue-collar and conservative Christian voters, served as president from 2017 to 2021, governing as a right-wing populist.

He was impeached twice by the House of Representatives, once in 2019 over his conduct regarding Ukraine and again in 2021 over the attack on the US Capitol by his supporters. He was acquitted by the Senate both times.

He leads his early rivals for his party’s nomination, holding the support of 43 per cent of Republicans in a February Reuters/Ipsos poll, compared with 31 per cent support for his nearest rival, Florida Governor Ron DeSantis, who has yet to announce his candidacy. President Biden is expected to seek re-election.

On March 18, Mr Trump wrote on social media that he had expected to be arrested on March 21 and urged his supporters to protest to “take our nation back”, reminiscent of his exhortations ahead of the January 6, 2021, attack on the US Capitol.

In 2018, Mr Trump initially disputed knowing anything about the payment to Ms Daniels. He later acknowledged reimbursing Mr Cohen for the payment, which he called a “simple private transaction”.

Ms Daniels has said she had a sexual encounter with Mr Trump at a Lake Tahoe hotel in 2006 – the year after he married his current wife Melania and more than a decade before the businessman-turned-politician became president.

The US Supreme Court in 2021 rejected her bid to revive a defamation lawsuit she brought against Mr Trump over a Twitter post in which he accused her of a “con job” after she described being threatened over publicising her account of a sexual relationship with him. Lower courts had thrown out her suit.

In the case that led to the conviction of the Trump Organisation on tax fraud charges, Mr Bragg declined to charge Mr Trump himself with financial crimes related to his business practices, prompting two prosecutors who worked on the probe to resign.

Among Mr Trump’s ongoing legal woes are a criminal investigation led by Fani Willis, the Democratic district attorney in Georgia’s Fulton County, into whether he unlawfully tried to overturn his 2020 election defeat in that state.

Special counsel Jack Smith is separately investigating Mr Trump’s handling of classified government documents after leaving office and his efforts to overturn the results of the 2020 election.

– with AAP