Twenty new plaintiffs joined a lawsuit Thursday against Michigan State University and Larry Nassar, alleging they were sexually abused by the former MSU sports doctor.The plaintiffs filed an amended complaint in federal court in Grand Rapids, bringing the total to more than 70 plaintiffs suing MSU and Nassar in state or federal courts.

The list of plaintiffs — current or former athletes who competed in gymnastics, swimming, figure skating, track and field, field hockey, basketball, tennis and soccer — are suing MSU, Nassar, USA Gymnastics and Twistars, a club southwest of East Lansing whose officials referred athletes to Nassar’s care. The plaintiffs, mostly minors at the time, allege Nassar assaulted them from 1996 to 2016.

The complaint alleges MSU, USA Gymnastics and Twistars failed to enforce policies against sexual harassment and assault or lacked adequate policies.

“This appears to be one of the largest sexual abuse scandals in the history of amateur athletics,” one of the plaintiffs’ lawyers, Stephen Drew, said in a statement Thursday.

An MSU spokesman could not be reached for comment immediately Thursday.

Earlier, Twistars issued the following statement: “We had zero knowledge of any of the allegations against Dr. Nassar, who was never an employee of Twistars. Our hearts go out to the women who have spoken up and, like everyone else, we are sickened to the core by their stories.”

One plaintiff alleges she was treated by Nassar for lower back and tailbone pain in 2002 when she was a 14-year-old gymnast.

She alleges Nassar digitally penetrated her vagina during appointments, including one attended by her mother.

The girl’s “… mother was trying to see what (Nassar) was doing, but (Nassar) moved around to block her view,” the plaintiff’s lawyer wrote.

The plaintiff “believes the conduct by (Nassar) was sexual assault, abuse, and molestation and for (Nassar’s) pleasure and self-gratification,” her lawyers wrote Thursday.

A second plaintiff, a former MSU student, alleges Nassar digitally penetrated her without gloves during treatments at Jenison Fieldhouse and the Duffy Daugherty building on MSU’s campus.

During one visit, Nassar was “breathing heavily while digitally penetrating her vagina,” according to the lawsuit.

A trainer knocked on the door and opened it and (Nassar) jumped up from his stool and walked away …,” her lawyers wrote.

In all, the plaintiffs in the case live in 11 states: Michigan, Kentucky, Washington, South Carolina, Illinois, California, North Carolina, Tennessee, Texas, Florida and Ohio.

“The women who are a part of this litigation seek institutional reform and accountability,” plaintiffs’ lawyer Adam Sturdivant said in a statement. “They do not want anything like this to ever happen again. They want to protect the next generation of athletes, and they want those who shared in the decisions and who were responsible for the lack of oversight which permitted these acts to occur to be held accountable.”

Nassar, 53, was a highly regarded physician at MSU and USA Gymnastics until September, when allegations emerged that he treated injured athletes with a procedure that involved him digitally penetrating female patients without a glove, lubricant or consent.

Simultaneously, MSU police are investigating more than 90 complaints.

Nassar is being held without bond and awaiting trial on three counts of first-degree criminal sexual conduct involving a person younger than 13, punishable by up to life in prison. He has pleaded not guilty.

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