A total of 145 former Ohio State University students have reported first-hand accounts of sexual misconduct by sports doctor Richard Strauss, investigators said in an update on Thursday.

More than 335 interviews have been conducted by Perkins Coie, the outside law firm hired to investigate allegations of abuse by the longtime university doctor. The firm said that fact-gathering could conclude by the fall.

Reading from a letter provided by the law firm Porter Wright, Ohio State Provost Bruce McPeheron explains the investigation is nearing its ending.

“Our best estimate is that assuming no additional avenues of investigation emerge, the fact-gathering phase of the investigation could draw to a close in the fall of this year,” McPheron said to a committee of trustees.

Hundreds of student athletes have alleged physical sexual abuse by Strauss, with allegations spanning from 1979 to 1997. Reports of abuse also emerged from Strauss' off-campus medical practice, which he established in 1996. Strauss died by suicide in 2005.

The investigative team is not just considering what happened, but what university officials knew at the time and what actions they did or did not take.

"The Perkins team's investigation into whether, and to what extent, Strauss may have examined high school-aged students during his time at the University is also ongoing," the letter reads.

Investigators are also looking into reports of a "sexually-exploitative atmosphere in Larkins Hall," the university's former gynmasium and swimming arena.

Reports have emerged from athletes in 16 different programs, including: wrestling, swimming, diving, water polo, cheerleading, volleyball, lacrosse, gymnastics, ice hockey, football, fencing, soccer, baseball, tennis, track and country, and golf.

The report shows attorneys leading the probe have also spoken with 95 university officials who worked at the school during Strauss’ tenure, and have examined 525 boxes of university records.

One problem that's emerged in the investigation is time: Decades have passed since Strauss was employed at the university, and potential witnesses are difficult to identify and track down. Some key witnesses have since passed away, investigators report.

Investigators expect to interview more employees, and will likely search hundreds more boxes of records, but don’t indicate exactly how many.

Earlier this month, the U.S. Department of Education's Office of Civil Rights opened its own investigation into the university. The probe will examine "whether the university is responding promptly and equitably to complaints and reports by former students, including allegations that employees knew or should have known about the sexual misconduct and allowed the abuse to continue."

More than a dozen former students are suing Ohio State, accusing school officials of ignoring complaints and even facilitating abuse by requiring physicals from Strauss. The lawsuits accuse the university of having "a culture of institutional indifference" about student safety, and claims Ohio State violated its Title IX responsibilities.