The committee has said it followed proper procedures and was told that the authorities were being contacted. But The New York Times in February identified at least 40 girls and women who said that Dr. Nassar molested them between July 2015, when he first fell under F.B.I. scrutiny, and September 2016, when he was exposed by The Star.

In November, Dr. Nassar pleaded guilty to sexually abusing seven girls, but at his sentencing hearing in January in Michigan, more than 150 girls and women described sexual abuse by him for years while they were under his care, either with the United States gymnastics teams, at private gyms or through his job at Michigan State. He was sentenced to 40 to 175 years in prison for multiple sex crimes. He had already been sentenced to 60 years in federal prison for child pornography convictions.

In January, Mr. Blackmun called for the resignation of the entire board of U.S.A. Gymnastics in the wake of the Nassar scandal, and days later the members complied. The head of U.S.A. Gymnastics had resigned last March.

U.S.A. Gymnastics, which sets the sport’s rules and policies and selects the American teams for the Olympics, has been widely derided for its handling of the sex-abuse scandal, but the U.S.O.C. has also come under scrutiny for its inability to hold the gymnastics federation accountable for its failures.

In his email demanding the resignation of the entire U.S.A. Gymnastics board, Mr. Blackmun wrote that the gymnastics federation needed “a categorically fresh start at the board level,” adding that “reform must start with an entirely new board.”