TAMPA, Fla. (AP) — Police are investigating the death of former NFL player Mike Williams in Tampa after getting information that he may have received unprescribed drugs from someone while hospitalized after a construction site accident.

The Tampa Police Department said in an email Tuesday that the probe involves “unprescribed narcotics by an outside party.” Williams died Sept. 12 at St. Joseph’s Hospital in Tampa at age 36, two weeks after he was injured in a construction accident that left him partially paralyzed.

“We take all allegations of criminal activity seriously, and detectives are working tirelessly on this active investigation,” the Tampa police email said. The investigation was first reported by the Tampa Bay Times. The Hillsborough County Medical Examiner’s office is also investigating the death.

Williams was revered in Buffalo for his football and basketball brilliance at Riverside High School, scholarship success at Syracuse University, and a five-year NFL playing career that culminated with his hometown Bills.

He is survived by his son, Mike Jr., 10, and daughter, Mya, 8. He had been accompanied by family in the hospital, including his mother Mary Rosenthal and brother Eric Baylor.

Williams’ on-the-job accident last month was not immediately thought to be life-threatening. Rosenthal told WIVB that Williams was doing electrical work when someone above him dropped a steel beam that struck Williams in the head. He thought he had walked away from the incident with just a headache, but his symptoms worsened that week.

Rosenthal said Williams was initially turned away from the hospital because they thought he only had a concussion, but was admitted days later when he began to lose feeling in his legs. He also developed a staph infection that contributed to his situation, Rosenthal said, adding that he underwent a surgery on his spinal cord while in the hospital.