The private detective at the center of a Fox News article about the death of a young Democratic aide claims that the White House and a wealthy Trump supporter urged the network to publish the article as part of a scheme to blunt speculation about the president’s ties to Russia, according to a lawsuit filed Tuesday.

Rod Wheeler, who was hired by the family of the aide, Seth Rich, to look into his death, said in the suit that the network fabricated quotations from him in an article about Mr. Rich on FoxNews.com. Mr. Wheeler states that the network was aware that he had not said the statements yet it published them “with reckless disregard for their truth.”

The network later retracted the article, saying it did not meet its standards.

In the suit, Mr. Wheeler, who is a Fox News contributor, asserts that he was a pawn in a broader plan by the White House, a Trump supporter named Ed Butowsky and Fox News to “shift the blame from Russia and help put to bed speculation that President Trump colluded with Russia in an attempt to influence the outcome of the presidential election.”

The lawsuit, alleging defamation and racial discrimination, was filed Tuesday morning in the United States District Court in the Southern District of New York. It named Fox News, 21st Century Fox, Mr. Butowsky and the author of the article, Malia Zimmerman, as defendants.