A grand jury has voted to indict Donald Trump over alleged payments to adult film actress Stormy Daniels, US media reports.
Amid speculation in recent weeks that he was due to be indicted, Mr Trump urged his supporters to protest against the authorities if he is detained.
He published a long statement describing the investigation as a “political witch-hunt trying to take down the leading candidate, by far, in the Republican Party”.
“I did absolutely nothing wrong,” he said, before criticising a “corrupt, depraved and weaponised justice system”.
The case – in which he is accused of making a payment to Ms Daniels towards the end of the 2016 presidential campaign in exchange for her silence over an alleged affair – is one of several related to Mr Trump.
Other ongoing cases include a Georgia election interference probe and two federal investigations into his role in the 6 January 2001 insurrection at the US Capitol.
The Manhattan District Attorney’s office has spent nearly five years investigating Mr Trump.
It has presented evidence to a New York grand jury that relates to a £114,000 ($130,000) payment to Ms Daniels.
Mr Trump has denied the alleged affair with Ms Daniels and accused her of extortion.