A student at Denver’s South High School reported being groped by two male classmates during a homecoming event in September – an allegation that sparked twin investigations of both the incident and the response of administrators, 9Wants to Know has learned.

Last Friday, a Denver Public Schools administrator announced in a letter to parents that South’s principal, Jen Hanson, and student advisor, Lynette Lucero, had been placed on leave but did not disclose what led to that decision.

Monday evening, a DPS spokesperson told 9NEWS two additional district employees have been placed on leave. That includes Sean Precious, instructional superintendent for DPS, and Barbara Downing, a school psychologist who handles disciplinary issues.

They are both on paid leave.

However, 9Wants to Know has learned that part of the sexual assault investigation is focused on whether school administrators followed a state law that requires them to report known or suspected abuse.

Denver Public Schools officials have repeatedly declined to provide details about the decision to place Hanson and Lucero on leave.

The alleged assault occurred on Sept. 14, in the middle of homecoming week, 9Wants to Know has learned.

A female South student reported that two male students groped her, according to a source familiar with the allegations. She also accused one of the boys of grabbing her hand and forcing her to touch him, the source said.

Denver police spokesman Sonny Jackson confirmed to 9NEWS that the department received a report of “inappropriate touching” on Sept. 27. Jackson said he could not disclose who called police, and the sequence of events between the alleged incident and the report to police 13 days later is not clear.

At the same time, he said the department is investigating the response of school officials to the girl’s allegations.

“We are aware of it and are looking into it,” Jackson said.

As for the sexual assault itself, Jackson said the girl’s parents did not want to go forward and press charges.

However, 9Wants to Know has learned that part of the case may not be over. District Attorney George Brauchler, whose district includes Arapahoe, Douglas, Elbert and Lincoln counties, has been named a special prosecutor in the sexual assault investigation. That move came after a request from Denver DA Beth McCann, who cited a conflict of interest.

Vikki Migoya, spokeswoman for Brauchler’s office, said she could not discuss the investigation.

The question of how school officials responded is rooted in Colorado’s mandatory reporting law.

It requires school administrators, teachers and many others – including doctors, cops, therapists, members of the clergy and scout leaders – to call police or social services if they have “reasonable cause to know or suspect that a child has been subjected to abuse or neglect.”

The letter sent to the families of South students on Friday, signed by Deputy Superintendent Susan Cordova, announced that the principal and student adviser had been placed on leave but did not elaborate.

“We have received information about concerns at our school that require a closer look,” Cordova wrote, in part. “While we look into these concerns, in order to be fair and thorough, we have placed Principal Jen Hanson and Student Advisor Lynette Lucero on administrative leave. This is standard practice in a review of this type and it does not imply or prejudge in any way what the review might determine. Please know we will share the results as fully as possible, as soon as possible.”

The letter provided no details on the “concerns” that “require a closer look.”

A message left Monday afternoon for the district’s chief communications officer, Nancy Mitchell, was not immediately returned.

On Saturday, district spokesman Will Jones said in an e-mail he could not elaborate.

“This case involves personnel matters,” Jones wrote to 9NEWS. “At this time, we cannot say anything more than what is in the letter.”

The new investigation comes on the heels of a decision by Denver District Attorney Beth McCann that charges would not be filed in the wake of shocking videos where multiple East High cheerleaders were physically forced into the splits by a coach.

Part of that investigation centered on the actions of school administrators once they learned about the videos.

In some of the videos, cheerleaders screamed in agony and begged the coach to stop. One girl suffered injuries, her parents told 9Wants to Know.

The coach, Ozell Williams, was fired, and the controversy led the East High Principal Andy Mendelsberg to retire and Athletic Director Lisa Porter to resign. Five assistant principals were also disciplined.

In that case, McCann’s office investigated both Williams and the response of school administrators.

In the end, McCann said that while the videos were “painful to watch” and she believed forcing the kids into the splits was inappropriate, she could not prove that a crime had been committed – either by the coach who carried out the technique or by school administrators who failed to notify police once they learned of it.

“If I don't believe that I can bring child abuse as a crime against the coach, then it is inconsistent to then file failure to report child abuse," said McCann.

Contact 9NEWS reporter Kevin Vaughan with tips about this or any story: kevin.vaughan@9news.com or 303-871-1862.