An amended lawsuit has been filed to add the US Center for SafeSport to a case which alleges the United States Olympic Committee (USOC) and USA Taekwondo (USAT) are guilty of "sex trafficking and negligence".
Female athletes have alleged the sport organisations sent them to competitions with "known predators".
The case was initially filed in April with taekwondo coach Jean Lopez and his brother Steven Lopez named as the defendants.
Both deny any wrongdoing.
The original lawsuit was brought forward by taekwondo athletes Mandy Meloon, Heidi Gilbert, Amber Means and Gabriella Joslin.
Jean Lopez has been accused of assaulting Meloon and Gilbert.
Gilbert reportedly claimed that Lopez had drugged and sexually assaulted her while Meloon accused him of molesting her.
A third woman has reportedly claimed he had also engaged in a consensual sexual relationship with her when she was 17.
Olympian Kay Poe has now added her name to the lawsuit.
It is alleged that Jean Lopez began sexually exploiting her and engaging in full sexual intercourse with her one year before the 1996 Olympics, when at 14 she became the youngest-ever member of the United States national team.
The lawsuit claims this was "a fact known to many in the USOC and USAT community".
By naming the US Center for SafeSport as a defendant in the lawsuit, it is alleged the organisation has "falsely held itself out to be an independent body which places the interests of athlete safety above those belonging to the USOC and its National Governing Bodies".
It is alleged that "SafeSport cannot effectively protect athletes from predators primarily because it is conflicted on account of the fact that the USOC entirely funds the entity".
The addition of the organisation to the case follows Jean Lopez’s sanction from them changing from "permanently ineligible" to a temporary restriction.
The Center declared him permanently ineligible for Olympic sport in the US in April after finding him guilty of two counts of sexual misconduct, including one involving a minor.
The change to the organisation's disciplinary records currently states there is an "Interim Measure - Restriction" against Lopez.
"This case will conclusively demonstrate that SafeSport is a sham," claimed attorney Robert Allard, a member of the legal team brining the case forward.
"We have seen case after case highlighted by the recent decision to reinstate alleged serial predator Jean Lopez where SafeSport bends over backward to protect coaches and, as a consequence, the financial interests of the USOC and its NGBs."
SafeSport chief executive Shellie Pfohl told US Today that the centre had sanctioned nearly 300 people since it opened in March 2017 and stated it was making a positive impact.
"The Center is making a positive impact both in responding to reports of abuse as well as working to change the culture of sport," Pfohl said.
"It is irresponsible to make baseless claims about the Center for one's own PR purposes as it could have a chilling effect on reports.
"The professionals at the Center for SafeSport are working tirelessly to protect athletes and to provide a safe place for victims to come forward, share their stories and to ultimately get a resolution when abuse occurred."
Stephen Estey, who represents several of the alleged victims, claimed last week that the Center had told him they would not be able to defend the lifetime ban unless the athletes testified in person at appeal hearings and be subject to cross-examination by them or their attorney.
This was denied by SafeSport spokesman Dan Hill, who stated that the centre offered "offsite questioning by video or telephone, as well as an opportunity for reporting parties to be questioned only by the arbitrator, without direct cross-examination by the responding party or their lawyer".
Lopez's brother Steven is also temporarily suspended amid an investigation into alleged sexual misconduct.
Lopez, Olympic gold medallist at Sydney 2000 and in Athens four years later, had been under interim restrictions since June 19.