The president's family business, the Trump Organization, received a subpoena Thursday from the office of Manhattan District Attorney Cyrus R. Vance Jr., according to an attorney for the company.
"This is a political hit job," said the lawyer, Marc L. Mukasey, in an email. "It's just harassment of the President, his family, and his business, using subpoenas and leaks as weapons. We will respond as appropriate."
The subpoena, first reported by The New York Times, was for records related to payments that former Trump lawyer Michael Cohen helped arrange to the porn actress Stormy Daniels after she claimed she had an affair with Trump.
Vance, whose office declined to comment, is a Democrat.
Federal prosecutors in New York and Washington both spent months probing payments made during the 2016 presidential campaign to two women who said they had affairs with Trump, including Daniels and the model Karen McDougal.
Cohen, who made one of the payments himself and arranged for American Media Inc., the parent company of the National Enquirer, to pay the other, pleaded guilty to campaign finance violations, tax evasion and other crimes and is serving a three-year sentence.
Trump, who denies any sexual relationship with either woman, has said that any payments were a personal matter, not a campaign expense.
The U.S. attorney's office in New York informed a court this month that it was finished investigating the payments. No one besides Cohen was charged, though prosecutors said in public court filings that Trump himself was aware of and directed the payments.
The Trump Organization also reimbursed Cohen for money he paid to Daniels. Cohen has argued that Trump Organization officials disguised the true nature of the payments and it is unfair that he is the only one prosecuted.
The federal inquiry looked at whether campaign finance laws were broken.
The New York Times reported, citing "people briefed on the matter," that Vance's inquiry involves an examination of whether anyone at the Trump Organization falsified business records by falsely listing the reimbursements to Cohen as a legal expense.
Falsifying business records can be a crime under state law.