The Michigan sports doctor Larry Nassar, who treated elite female US gymnasts, has been charged with sexually assaulting nine girls.
On Wednesday, Michigan Attorney General Bill Schuette filed 22 counts of criminal sexual conduct, some involving girls younger than 13.
He described Dr Nassar, accused of molesting gymnasts as he treated back and hip injuries, as "a monster".
The doctor has denied allegations of abuse in the past.
Dr Nassar has said he was carrying out legitimate procedures.
He is already being held on a charge of possessing child pornography and faces trial over accusations he abused a girl repeatedly at her family home.
'More times than she could count'
The 53-year-old doctor, who has treated Olympic gymnasts, is accused by more than 60 former patients and athletes of sexual abuse during pelvic procedures.
He was stripped of his medical licence last month, amid at least six criminal and civil lawsuits.
Dr Nassar was fired in September after working for decades as a doctor for gymnasts at Michigan State University, as well as USA Gymnastics - the sport's governing body.
The new charges relate to work he did at Michigan State University's Sports medicine clinic and at a gymnastics club called Geddert's Twistars in Eaton County.
Parents were either asked to leave the room while the abuse took place or Dr Nassar used a sheet or stood in a position to block any view, police said.
A girl identified as Victim B, now 21, said she was sexually assaulted by Dr Nassar "more times than she could count," Det Sgt Andrea Munford wrote in an affidavit.
Victim B said "all the gymnasts trusted Nassar and that he was like a god to the gymnasts", she added.Allegations increasing
"This guy is disgusting. This guy is despicable,'' said Mr Schuette. "Dr Nassar used his status and authority to engage in horrid sexual assaults under the guise of medical procedures."
Dr Nassar's lawyers declined media requests for comment on Wednesday, but he has previously denied abuse.
Police say allegations against him continue to increase almost daily. Three former members of the US gymnastics team described their experiences on CBS's "60 Minutes" show on Sunday.
"He would put his fingers inside of me, move my leg around,'" said Olympian Jamie Dantzscher, a member of the bronze-medal-winning American team at the 2000 Olympics in Sydney.
"He would tell me I was going to feel a pop and that that would put my hips back and help my back pain.''
Allegations of sexual assault were first revealed by the Indianapolis Star newspaper in September 2016 when he was accused by two former gymnasts.
Since then, more than 60 women have accused him, and at least 40 have filed lawsuits.
Several of those suits name USA Gymnastics as a co-defendant, claiming they had not done enough to prevent the abuse.