The University of Michigan says it’s investigating multiple “disturbing and very serious” allegations of sexual abuse against a former member of its campus medical team.

Robert E. Anderson was the director of the University Health Service and spent several years as a top physician for school’s football team from 1968 until 2003 when he retired. He passed away in 2008.

In July 2018, the university quietly launched an investigation into Anderson after a former student athlete wrote to the university’s Athletic Director Warde Manuel about alleged abuse he suffered during a medical exam performed by Anderson in the early 1970s.

Robert Julian Stone claimed Anderson, a married father of three at the time, abused during a checkup on June 30, 1971. While explaining how to check for STDs, the doctor allegedly dropped his pants then reached for Stone’s hand and placed it on his penis.

Another time, Stone says Anderson performed a medically unnecessary rectal examination on him, for which he still has the official medical file written in Anderson’s handwriting.

Speaking to the Detroit News, Stone says: “When I first wrote to the university, I thought, ‘Well, Dr. Anderson was a closeted gay man,’ and I had some compassion for a man at that time in that position. Now I realize he wasn’t a closeted gay man. He was a sexual predator and that’s … a criminal thing.”

After Stone spoke out in 2018, more former student athletes came forward to say they, too, had suffered sexual abuse at the wandering hands of Anderson. The victims all described sexual misconduct and medically unnecessary exams, including rectal exams, beginning in the early 1970s and lasting all the way up through the late 1990s.

The university is now calling on any addition victims to please come forward, and has even opened a hotline for people to call.

“The allegations that were reported are disturbing and very serious,” says U-M President Mark Schlissel. “We promptly began a police investigation and cooperated fully with the prosecutor’s office.”

“As part of our commitment to understanding what happened and inform any changes we might need to make, we now are taking the next step to reach out to determine who else might be affected or have additional information to share. Every person in our community should expect to feel safe and supported.”

Stone says going public with his story wasn’t easy, but he hopes it helps encourage others to do the same.

“I don’t think any man would really want to be the face of male sexual assault survivors in the 21st century,” he says. “But if men don’t start coming forward, these things are just going to go on.”

Related: 21 men are now accusing college doctor of performing medically unnecessary rectal examinations