The family of President Donald Trump is asking a court to block the publication of a forthcoming tell-all book written by Trump's niece, Mary Trump, her lawyer and publisher confirmed Tuesday.
The New York Times, citing a person familiar with the matter, first reported Tuesday afternoon that Trump's brother, Robert Trump, sought a restraining order against Mary Trump and the publisher Simon & Schuster in Queens County Surrogate's Court in New York.
That is the same court that handled the estate of the president's late real estate developer father, Fred Trump Sr. Mary is the daughter of Fred Trump Jr., the president's late older brother.
President Trump has said that Mary Trump, 55, signed a nondisclosure agreement when she settled a court fight related to the estate.
"She's not allowed to write a book," Trump told the news site Axios last week.
The White House declined to comment for this article.
Mary's book, "Too Much and Never Enough: How My Family Created the World's Most Dangerous Man," is scheduled to be published on July 28. Despite no physical copies being available for sale yet, the book is No. 5 on the Amazon.com bestseller list as a result of pre-publication sales.
The Daily Beast earlier reported the existence of the nondisclosure agreement, and the expectation that Mary Trump would out herself in the book as having been the primary source for the Times' Pulitzer Prize-winning series about President Trump's finances.
The Times stories relied on tax returns by the president's father, Fred Trump Sr., and other private family financial records.
Simon & Schuster on its website says Mary Trump's book is a "revelatory, authoritative portrait of Donald J. Trump and the toxic family that made him."
Robert Trump told The Times in a statement Tuesday that he was "deeply disappointed" in his niece's decision.
"Her attempt to sensationalize and mischaracterize our family relationship after all of these years for her own financial gain is both a travesty and injustice to the memory of my late brother, Fred, and our beloved parents," Robert Trump said.
Mary Trump's lawyer, Theodore Boutrous, in a statement provided to CNBC, said, "President Trump and his siblings seek to suppress a book that will discuss matters of utmost public importance."
"They are pursuing this unlawful prior restraint because they do not want the public to know the truth. The courts will not tolerate this brazen violation of the First Amendment," Boutrous said.
Simon & Schuster in a statement said, "As the plaintiff and his attorney well know, the courts take a dim view of prior restraint, and this attempt to block publication will meet the same fate as those that have gone before."
"In Too Much and Never Enough: How My Family Created the World's Most Dangerous Man, Mary Trump has written a compelling personal story of worldwide significance, and we look forward to helping her tell her story," the publisher said.
Trump several days ago lost a court battle to try to stop publication of a memoir by his former national security advisor John Bolton.
Simon & Schuster is also the publisher of Bolton's book, entitled, "The Room Where it Happened."
That book, which went on sale this week, is No. 1 on the Amazon bestseller list.