Former Olympic swimmer Ariana Kukors Smith joins OTL to speak out about the abuse she says she suffered at the hands of her former coach. (4:46)

SEATTLE -- Olympic swimmer Ariana Kukors Smith sued USA Swimming on Monday, alleging that the sport's national governing body knew her former coach sexually abused her as a minor and failed to protect her while shielding him.

Kukors Smith alleges that Sean Hutchison, who began coaching her at a swim club near Seattle, groomed her for sexual abuse when she was 13, started touching and kissing her when she was 16 and engaged in sexual activity with her when she was 17.

"This lawsuit is about holding people accountable who should have protected a 15-year-old girl," Kukors Smith told reporters, adding, "I needed help, and there were people in positions of power that could have helped me."

Hutchison has denied the allegations, which emerged earlier this year when Kukors Smith, now 28, posted an emotional essay online. Hutchison, an assistant coach on the 2008 U.S. Olympic team, has not been charged with a crime. The office of his attorney, Brad Meryhew, said he had no comment on the lawsuit.

The case marked another scandal for USA Swimming and for the sports world, which has faced accusations that coaches and others, including former USA Gymnastics sports doctor Larry Nassar, exploited their positions to sexually abuse athletes in their care.

The U.S. governing body of swimming said it first learned of the underage abuse allegations when Kukors Smith -- the 2009 world champion in the 200-meter individual medley, who placed fifth in that event at the 2012 Games -- posted her essay in February.

"As expressed earlier this year, we respect Ariana Kukors' bravery in stepping forward and sharing her story," USA Swimming said in a statement Monday. "We have been in regular contact with her legal team over the last several months and will continue to work with them and Ariana through this process."

The lawsuit says top USA Swimming officials were well aware in 2005 that Hutchison had an inappropriate relationship with Kukors Smith, who was then 16. The lawsuit alleges that officials did not report it to authorities and didn't protect Kukors Smith.

Top officials at the organization, according to the lawsuit, also manipulated a background screening system to shield coaches, including Hutchison, from a negative background check.

They "secretly agreed that Hutchison should be specifically protected from the background check process due to the fact that pervasive rumors of his inappropriate sexually motivated behavior towards minors such as the plaintiff would inevitably surface through contacts with prior employers," the lawsuit said.

Kukors Smith said "organizations like USA Swimming have long been in a position to deter, detect and discipline sexual abuse and have done little or nothing to do such in an effort to protect their public image. By doing nothing, it enabled Sean Hutchison to abuse me for a decade."

The lawsuit, which was filed in Superior Court in Orange County, California, seeks unspecified damages. It also names longtime Olympic coach Mark Schubert, saying he failed to report "a reasonable suspicion of child abuse or endangerment."

A number for him could not immediately be found.

"I wanted to believe that an organization like USA Swimming had my best interest at heart and that they were there to protect me," Kukors Smith said in an interview with The Associated Press in a Seattle hotel room. "Over these last few months, I've realized that that is not the case. That not only were they not protecting me, but they were knowingly not protecting me and kept me in harm's way."

She said she and her husband, Matt Smith, hope to have kids one day and want to make sure the sport is safe.

"We can't prevent this from happening unless the people at USA Swimming, at these organizations, Sean Hutchison take responsibility for what they did," she said.

USA Swimming hired a private investigator in 2010 to look into rumors of a relationship between Kukors, then 21, and Hutchison, then 39. USA Swimming said it closed the investigation without finding any misconduct after the two and others denied the relationship.

The lawsuit alleges that the organization engaged in "a sham investigation" to protect itself and Hutchison.

USA Swimming revealed in 2010 that sex abuse allegations were mostly to blame for lifetime bans of 46 members and said it set up training and enhanced screening for all coaches, officials and volunteers.