Mary Trump identified herself as a Times source in her 2020 tell-all, "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man"
Mary Trump and her uncle Donald Trump.
A New York state appeals court said Donald Trump can sue his niece Mary Trump for giving the New York Times information for its Pulitzer Prize-winning 2018 probe into his finances and his alleged effort to avoid taxes.
The Appellate Division in Manhattan found a "substantial" legal basis for Donald Trump to claim that his niece violated confidentiality provisions of a 2001 settlement over the estate of his father, Fred Trump Sr.
A five-judge panel said it was unclear whether Mary Trump's disclosures were subject to confidentiality, or how long both sides intended the provisions to remain in effect.
"At a minimum, nominal damages may still be available on the breach of contract claim even in the absence of actual damages," the court said. Donald Trump had sought $100 million.
Lawyers for Mary Trump did not immediately respond to requests for comment.
They had argued that Donald Trump's lawsuit violated a state law to stop litigation designed to "chill and retaliate against" free speech, including communications with the press.
Alina Habba, a lawyer for the former U.S. president, said Trump looked forward to holding Mary Trump "fully accountable for her blatant and egregious breach of contract."
Thursday's decision upheld a June 2023 ruling by Justice Robert Reed of the state Supreme Court.
Reed also dismissed Donald Trump's claims against the Times and three reporters, and in January ordered him to pay $392,639 of their legal fees.
In November 2022, Reed dismissed Mary Trump's separate lawsuit accusing her uncle and two of his siblings of defrauding her out of a multi-million-dollar inheritance.
The Times' reporting challenged Donald Trump's claim that he was a self-made billionaire.
It said he received the equivalent of $413 million from his father, largely the result of "dubious" tax schemes in the 1990s, including undervaluing his family's real estate holdings. Donald Trump has denied wrongdoing.
Mary Trump, a psychologist, identified herself as a Times source in her 2020 tell-all, "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man."
The case is Trump v Trump, New York State Supreme Court, Appellate Division, 1st Department, No. 2023-03021. (Reporting by Jonathan Stempel in New York; Editing by Rod Nickel)