Fox News and its parent company, 21st Century Fox, have filed a motion to move the defamation and racial discrimination lawsuit involving a Fox News article about the death of a young Democratic aide from a New York federal court to arbitration.

In the alternative, Fox said that the lawsuit should be dismissed, calling the claims “without merit and legally insufficient” and saying that the “defamation claim is itself founded on a falsehood.”

The lawsuit was filed in August by Rod Wheeler, a private detective who was hired by the family of the aide, Seth Rich, to look into his death. Mr. Wheeler said in the suit that the network fabricated quotations from him in an article about Mr. Rich on FoxNews.com. The article was retracted after it was published, with the network saying it did not meet its standards.

Mr. Wheeler, who is a Fox News contributor, claimed in the suit that the network was aware that he had not said the statements yet it published them “with reckless disregard for their truth.” Mr. Wheeler also asserted that he was a pawn in a broader scheme 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.”