Updated at 2:45 p.m. ET

Olympic gymnast Aly Raisman filed a lawsuit Wednesday against the U.S. Olympic Committee and USA Gymnastics, saying the organizations "knew or should have known" about team doctor Larry Nassar's longstanding, widespread abuse, and yet failed to act.

Raisman says she suffered "serial molestation, sexual abuse and harassment" by Nassar, a "trusted" team physician, who is also named in the lawsuit.

Some 200 girls and young women have made similar accusations against the disgraced doctor, who has pleaded guilty to child pornography and criminal sexual misconduct charges. Nassar is behind bars after receiving prison sentences of up to hundreds of years.

Raisman, a six-time Olympic medalist and former team captain, says in the complaint that Nassar sexually abused her at the Karolyi Ranch national training center and at competitions both in the United States and abroad, including at the 2012 Summer Olympics in London.

Raisman's lawyer John Manly said in a statement that the USOC and USA Gymnastics "conspired to hide their knowledge of Nassar's horrible crimes from the public and attempted to frighten Ms. Raisman and other victims into keeping quiet."

Raisman told CNN that after speaking with an investigator hired by USA Gymnastics in 2015, she felt threatened and believed she would jeopardize herself if she continued to speak out.

The lawsuit says Nassar was disciplined several times by the USOC and USA Gymnastics for inappropriate behavior, yet was allowed to continue treating athletes.

Raisman's lawsuit also alleges the USOC and USA Gymnastics "willfully refused to notify, give adequate warning and implement appropriate safeguards" regarding Nassar's "deviant sexual behavior and propensities."

USA Gymnastics says it "acted without hesitation" after learning of "athlete concerns" in the summer of 2015. According to its timeline, it fired Nassar on July 29, about a month after launching an investigation.

"USA Gymnastics supports our athletes, like Aly Raisman," the organization said in a statement Friday shared with NPR. "(A)nd we are very sorry that any athlete has been hurt by the despicable crimes of Larry Nassar."

"USA Gymnastics is committed to doing everything we can to prevent this from happening again," the statement said.

The USOC did not respond to NPR's request for comment.

The complaint says that the trauma of Nassar's abuse led to depression and fear for Raisman and that she has lost millions of dollars as a result. The suit is seeking unspecified damages for past and future earnings.

"My highest priority has been to push for change, so future generations of athletes will be safer," Raisman said in a statement sent to NPR and other media outlets. "It has become painfully clear that these organizations have no intention of properly addressing this problem. After all this time, they remain unwilling to conduct a full investigation, and without a solid understanding of how this happened, it is delusional to think sufficient changes can be implemented."

The lawsuit was filed on the same day that USOC chief executive Scott Blackmun announced his resignation, citing health issues. The committee also has announced a series of reforms it is taking in the wake of the scandal, including providing more counseling for gymnasts impacted by Nassar's crimes, undertaking a review of the USOC's governance structure and "ensuring that athletes have a stronger voice within the USOC."

For its part, USA Gymnastics says it has made several "bold decisions and actions" including closing the National Team Training Center at the Karolyi Ranch and creating an athlete task force to let athletes help shape the organization's operating decisions.

The Associated Press reports that more than 100 civil actions have been filed against USA Gymnastics and Nassar, including a lawsuit by Raisman's onetime Olympic teammate McKayla Maroney

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