NEW YORK (Reuters) - A man who said he was sexually assaulted at age 14 by the actor Kevin Spacey in the 1980s must identify himself if he is to continue his $40 million civil lawsuit against the Oscar winner, a federal judge ruled.

US District Judge Lewis Kaplan said on Monday that Spacey’s fame “magnified” the public’s legitimate interest in knowing the identity of the plaintiff, known as “C.D.”

The Manhattan judge also said it would also unfairly burden the 61-year-old Spacey by forcing him to defend against an unknown accuser.

C.D. “makes serious charges and, as a result, has put his credibility in issue,” Kaplan wrote. “Fairness requires that he be prepared to stand behind his charges publicly.”

Kaplan gave the plaintiff 10 days to amend his complaint and include his name.

Lawyers for C.D. and Spacey did not immediately respond on Tuesday to requests for comment.

C.D. said he was 12 when he met Spacey in 1981 as a student in his acting class in Westchester County, New York.

He said he began a sexual relationship with Spacey two years later in New York City, and that it ended after he resisted Spacey’s attempts to penetrate him.

A co-plaintiff, actor Anthony Rapp, said he was 14 when Spacey engaged in an unwanted sexual advance with him during a 1986 party at Spacey’s home. He is also seeking damages.

In a court filing last November, Spacey denied C.D.’s and Rapp’s sexual misconduct accusations.

He had said in 2017 he did not recall the alleged encounter with Rapp, but that if he behaved as described he owed an apology “for what would have been deeply inappropriate drunken behavior.”

Spacey’s awards for acting include Oscars for “American Beauty” and “The Usual Suspects,” a Golden Globe for Netflix’s “House of Cards” and a Tony for Neil Simon’s “Lost in Yonkers.”

Netflix severed its ties with Spacey after sexual misconduct accusations surfaced in 2017.