Mr. Jordan served as an assistant coach on the Ohio State wrestling team in the late 1980s and early 1990s, during which time Dr. Strauss is accused of showering with athletes and touching them inappropriately. The university announced in April that it had begun investigating the allegations against the doctor, who killed himself in 2005.

Mr. Coleman and four other wrestlers have now said that Mr. Jordan was aware of the abuse but did nothing to stop it. Another former Ohio State wrestler, Mike Schyck, said in an interview on Friday that he and other former team members planned to “collectively say some things together,” adding that the scandal is not about Mr. Jordan.

But even as more wrestlers step forward, Mr. Jordan’s base has mounted a defense. The conservative news media has questioned the motives and truthfulness of his accusers.

One of those accusers, Mike DiSabato, scoffed at suggestions that his motivation in calling out Mr. Jordan was political or part of a personal vendetta.

“There were two choices for Jim when he was asked about this situation: He could have told the truth that he saw it, he was there, he was in the showers and saunas with us,” Mr. DiSabato said. “He could have told the truth and stood with us, or he could have played politics.”

Mr. DiSabato said he was saddened by the congressman’s response.

“I’m sorry, I love Jim Jordan, but he doesn’t get to call me a liar to the entire world,” Mr. DiSabato said. “He doesn’t get to call the victims of systemic sexual abuse liars. He doesn’t get to act like he wasn’t in the sauna with us every day being subject to voyeurism.”

The allegations have cast a cloud over the congressman at a time when he is ascendant. Mr. Jordan has emerged as one of the president’s staunchest defenders, helping to lead a Republican counterinvestigation of F.B.I. and Justice Department officials who are looking into potential connections between the Trump campaign and Russian election interference. A founder of the House Freedom Caucus, Mr. Jordan has also been floated as a possible successor to Speaker Paul D. Ryan of Wisconsin, who has announced he will retire at the end of the year.