New York County District Attorney Cyrus Vance’s office has subpoenaed eight years of President Donald Trump’s tax returns from Mazars USA, the longtime accounting firm to Trump and the Trump Organization, as part of its investigation into hush money payments, according to a person familiar with the matter.

The subpoena was first reported by The New York Times.

It isn’t clear what deadline Mazars USA has to comply with the grand jury subpoena. A Mazars representative could not immediately be reached for comment.