A New York doctor who illegally distributed painkillers and solicited sexual favors from some younger patients in exchange for opioid prescriptions has been sentenced to nearly five years in prison, federal prosecutors in New Jersey announced Thursday.

Joseph Santiamo, 65, of Staten Island, had pleaded guilty last December to conspiracy to distribute oxycodone. He received a 57-month prison term and will have to serve three years of supervised release once he's freed.

Santiamo owned and operated an internal medicine and geriatric care practice from January 2012 through May 2018. He prescribed large amounts of oxycodone without legitimate medical reasons for the treatments, prosecutors said, and also solicited sexual favors from some younger patients in exchange for opioid prescriptions.

These patients were all under 40 at the time they got prescriptions from Santiamo prosecutors said, noting people of that age would not usually be treated by a geriatric care physician. In some instances, Santiamo provided the prescriptions despite evidence that some patients were abusing opioids, prosecutors said.

Federal authorities charged Santiamo as part of an investigation targeting health care fraud across the Northeast, prosecutors have said. The case was investigated by agents with the Drug Enforcement Administration’s New Jersey division.