An investigation undertaken by the Indianapolis Star has claimed that "at least" 368 American gymnasts have made allegations of sexual abuse in the past 20 years.

Nassar, who served in the USA Gymnastics role from 1996 until 2015, has been accused of molesting dozens of patients.

He possessed "thousands of images of child pornography" between 2003 and 2016, according to a two-count indictment filed in Michigan. 

He is now being held until a detention hearing on Wednesday (December 21).

Two women have filed lawsuits against both Nassar and USA Gymnastics. 

One, an unnamed former Olympic medalist, says she was molested for several years in the mid-1990s from the age of 13. 

The other, reportedly also a former member of the US national team, claimed other coaches ignored abuse at their training centre in Texas.

It is claimed that abuse took place under the guise of invasive medical examinations.

Nassar has denied all molestation charges and his lawyers claim any "procedures" he performed were medically sound.

A nine-month investigative report by the Indianapolis Star also claimed that 115 adults "at every level of the sport" are implicated in the abuse.

USA Gymnastics announced last month that lawyer Deborah Daniels will conduct an independent review of the organisation following allegations of "sexual misconduct".

The organisation claims it severed ties with Nassar in 2015 when first learning of the testimonies against him

They claim to be "proud of the work it has done to address and guard against child sexual abuse".