Four new complaints filed against Larry Nassar, including one dating to '92

Additions to a civil lawsuit against Larry Nassar claim that the former Michigan State and USA Gymnastics team doctor sexually assaulted women as early as 1992, before he completed medical school and became a licensed doctor.

Four more women filed complaints this week against Nassar, 53, who has been accused of digitally penetrating scores of women -- many of whom were minors at the time -- while treating them for athletic injuries. Nassar and his attorneys have maintained that the alleged abuses were part of legitimate medical procedures.

More than 90 women have joined a total of 10 civil lawsuits in federal and state courts against the former doctor. Michigan State confirmed that more than 100 women have contacted the university's police department with information about past assaults.

The newest addition to one of the federal lawsuits claims that Nassar sexually assaulted a woman in his apartment in Michigan while he was still a medical student in 1992. That is the earliest claim against Nassar to date; previously, U.S. Olympian Jamie Dantzscher had said Nassar started abusing her in 1994.

The woman said Nassar invited her to his apartment when she was between the ages of 12 and 14, according to the lawsuit. He asked her to participate in some medical research he was doing and offered her a free full-body massage as compensation. The woman alleges that during the massage, Nassar penetrated her vaginally.

The three other women who joined the lawsuit this week say that Nassar assaulted them within the past five years. Those three, according to the suit, were between the ages of 12 and 15 when the alleged assaults began.

Nassar completed medical school at Michigan State in 1993 and finished his residency in 1996.

Nassar has been charged with 25 counts of first-degree criminal sexual conduct, each a felony that can carry up to a lifetime prison sentence if he is convicted. He has also been charged with possession of child pornography and has remained in federal custody for those charges since December.

Michigan State fired Nassar in September 2016. USA Gymnastics cut ties with him in the summer of 2015. His medical license was revoked earlier this month.