Former US President Donald Trump will be charged over hush money payments made to a porn star just before the 2016 presidential election.

The details of the case against him have not yet been released.

A grand jury has voted to indict him after investigating a $130,000 pay-out to Stormy Daniels in an attempt to buy her silence over an alleged affair.

Mr Trump, 76, denies wrongdoing. He is the first serving or former US president to face a criminal charge.

The office of Manhattan District Attorney Alvin Bragg, who has been pursuing the investigation, confirmed that it had contacted Mr Trump's attorney to "co-ordinate his surrender" on unspecified charges.

The ex-president, who lives in Florida, is expected to fly to New York on Monday and be arraigned in court on Tuesday, two sources familiar with the matter told CBS News, the BBC's US partner.

The charges in the indictment will be read to him at the hearing, which is set to last about 10-15 minutes.

The United States Secret Service - which is tasked with protecting serving and former US presidents - will be in charge of security for the court appearance.

In 2016, adult film star Stormy Daniels contacted media outlets offering to sell her account of what she said was an adulterous affair she had with Donald Trump in 2006 - the year after he married his current wife, Melania.

Mr Trump's team got wind of this, and his lawyer Michael Cohen paid $130,000 to Ms Daniels to keep quiet. This is not illegal.

However, when Mr Trump reimbursed his lawyer, the record for the payment says it was for legal fees. Prosecutors say this amounts to Mr Trump falsifying business records, which is a misdemeanour - a criminal offence - in New York.

Prosecutors could also potentially allege that this breaks election law, because his attempt to hide his payments to Ms Daniels were motivated by not wanting voters to know he had an affair with her.

Covering up a crime by falsifying records would be a felony, which is a more serious charge. Even advocates for prosecution acknowledge that either way, this is by no means a clear-cut case.

There is little precedent for such a prosecution, and past attempts to charge politicians with crossing the line between campaign finance and personal spending have ended in failure.

Mr Trump now faces the prospect of having his fingerprints recorded and his mugshot taken, like all defendants in criminal cases.

In a statement, Mr Trump lashed out at the Manhattan district attorney. He called the prosecutor a "disgrace", and accused him of "doing Joe Biden's dirty work".

"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.

Mr Trump has repeatedly slammed the investigation in his hometown of New York as a political "witch hunt" led by his opponents.

Mr Bragg, who is a registered Democrat, has denied pursuing a political vendetta against Mr Trump. "We evaluate cases in our jurisdiction based on the facts, the law, and the evidence," he tweeted earlier this month.

Mr Trump's lawyer, Susan Necheles, said in a statement: "He did not commit any crime. We will vigorously fight this political prosecution in court."

Following the indictment, Ms Daniels thanked her supporters. "I have so many messages coming in that I can't respond... also don't want to spill my champagne," she tweeted.

The criminal case could shape the 2024 presidential race. Mr Trump is currently the front-runner among all declared and potential contenders for the Republican White House nomination.

But there is nothing in US law that prevents a candidate who is found guilty of a crime from campaigning for, and serving as, president - even from prison.

His campaign sent out fundraising emails on Thursday evening, citing the indictment.

Top congressional Republicans are rallying behind Mr Trump.

House of Representatives Speaker Kevin McCarthy said: "Alvin Bragg has irreparably damaged our country in an attempt to interfere in our Presidential election.

"As he routinely frees violent criminals to terrorize the public, he weaponized our sacred system of justice against President Donald Trump."

But Democrats welcomed the indictment, arguing it showed no-one was above the law.

Congressman Adam Schiff said: "The indictment and arrest of a former president is unique throughout all of American history.

"But so too is the unlawful conduct for which Trump has been charged."

Mr Trump is also being investigated in several other cases.

They include probes into his role in the US Capitol riot of January 2021, his efforts to overturn his loss in the state of Georgia in the 2020 election, and his handling of classified documents after leaving office.

Mr Trump - who served as president from 2017-21 - was twice impeached by the House of Representatives. He was acquitted by the Senate both times.