Prosecutors in Ohio are investigating a doctor who health officials claim allegedly prescribed “significantly excessive and potentially fatal” doses of fentanyl to as many as 27 patients who later died. William Husel, who worked at Columbus’ Mount Carmel Hospital, is accused of intentionally giving lethal doses of the potent opioid to dozens of patients. The Franklin County Prosecutor’s Office is investigating. CBS News reported Husel was fired in December after initial complaints, and 23 caregivers at the hospital were also placed on leave. Christine Allison, whose 44-year-old husband, Troy, died after allegedly being administered fentanyl by Husel, has filed a lawsuit against the doctor and the hospital for what the civil suit claims was “a lethal dose of fentanyl.” She has been joined by other families who allege their loved ones were intentionally prescribed the drug to terminate their lives. In two reported cases, Husel is accused of prematurely deciding the patient had irreparable brain damage severe enough to end their lives.

Mount Carmel Hospital CEO Ed Lamb has since apologized, saying in a statement that “this doctor ordered significantly excessive and potentially fatal doses of pain medication for at least 27 patients who were near death." However, Husel’s attorney told CBS News. “We dispute the hospital’s characterization and continue to review the patient records” provided to the legal team.