As reported by the Boston Globe, Steven Ungerleider filed the suit in federal court in Boston on Friday, claiming defamation and tortious interference. In his complaint, Ungerleider says Angela Ruggiero, a former Harvard hockey player and four-time Olympic medalist, tried to undermine his work by defaming him to Olympic officials.

Responding to Ungerleider’s complaint, USOC spokesman Patrick Sandusky said in an e-mail Friday night, “We do not believe this is a valid lawsuit and plan to defend ourselves vigorously.”

Ruggiero’s lawyer, Michael J. Grygiel, said in a statement Friday night that Ungerleider’s claims are frivolous and said his decision to file the suit was ill-advised. The complaint’s allegations, he said, “are pulled out of thin air and have no basis in reality.”

“Through her association with the USOC and [the International Olympic Committee], and as a matter of personal conviction, Ms. Ruggiero stands with the survivors and unreservedly supports full transparency in the investigation of sexual abuse cases involving USA Gymnastics — or any other athletic program or organization — and the legal prosecution of those responsible,” Grygiel said in his statement.

Ungerleider’s suit names Ruggiero as a member of the USOC’s board of directors and an executive board member of the International Olympic Committee. A spokeswoman for Ruggiero said in an e-mail early Saturday that Ruggiero left both boards last month, as both of her terms were up at the end of the Winter Olympics in South Korea.

In his suit, Ungerleider said Ruggiero called him a liar and a fraud who was manipulating sexual abuse survivors.

Ungerleider has recently “focused on confronting the sexual abuse crisis in gymnastics,” according to his suit.

In recent years, he has spoken to more than 100 athletes who survived sexual abuse, as part of a project that is intended to ensure “that the abuse is properly acknowledged and to serve as an educational resource to help [prevent] its recurrence,” according to the complaint.

In court documents, Ungerleider said he has been assembling a commission that was intended to work with Olympic agencies to “address the crisis in amateur sports such as gymnastics and swimming.”

The systematic abuse of athletes by former USA Gymnastics team doctor Larry Nassar detailed in recent months has been called the worst sex-abuse case in sports history. Last month, he was sentenced to 40 to 125 years for molesting young athletes at a Michigan gymnastics club, and he has two other prison terms to serve, including a 60-year federal prison bid for child pornography charges.

According to Ungerleider’s complaint, more than 265 girls and women “have come forward to document Nassar’s abuse.” That group includes six-time Olympic medalist Aly Raisman, a Needham native.

In his complaint, Ungerleider said USA Swimming has also been plagued by sexual abuse and sexual misconduct in past years and that attempts at creating new protections for athletes have been flawed.

Ungerleider, who lives in Oregon, alleges that Ruggiero defamed him during four conversations with sports officials, according to the complaint. In one phone call with an Olympic official, she called him a fraud and said he was manipulating “athletes to make false statements and their allegations in order to exaggerate the sexual abuse crisis,” according to Ungerleider’s suit.

She repeated the assertion he was manipulating sexual abuse victims in another discussion with an Olympic official, according to Ungerleider’s complaint.

Ungerleider asserts that in at least two other conversations Ruggiero had with Olympic luminaries, she said he had lied or fabricated information about a sexual abuse crisis in US Olympic sports.

“Ruggeiro has worked to keep quiet the extent of the sexual abuse crisis in U.S. Olympic sports, in large part, because of her efforts to bring the Olympic Games to Los Angeles, which she believes would be jeopardized should the sexual abuse scandal continue to garner attention,” reads Ungerleider’s complaint.

Last summer, Los Angeles was awarded the 2028 Summer Olympics. Ungerleider claims in his suit that a company owned by Ruggiero received at least $60,000 in consulting fees as part of that bidding process.

When Ungerleider complained to Ruggiero about her comments, the USOC stripped him of all his positions with that organization, including a USOC accreditation “from which he receives the bulk of his counseling clients,” according a statement from a law firm that is representing him.

The USOC, according to the complaint, removed Ungerleider “from these posts as a direct result of Ruggiero’s improper actions in retaliation against” him.

Ungerleider blames Ruggiero and the USOC’s interference for harming him financially. In his complaint, he said he has lost more than $75,000 because of lost business relationships, and that he could lose more business relationships because of their actions, according to the complaint.