Dr. Eric Jacobson is not under arrest but federal agents descended on his Great Neck office as part of an investigation into the distribution of painkillers on Long Island.
Jacobson had prescribed thousands of painkillers for Laffer and his wife Melinda Brady, months before Laffer killed four people while robbing a Medford pharmacy for painkillers.
"What he did was a sick act, and had nothing to do with me prescribing him medication," Jacobson said Thursday.
"Laffer as far as I knew wasn't seeing other doctors," said Jacobson. "He was as normal as anyone you would ever meet. He was a model patient -- never came in early for any medications, had legitimate injuries which required treatment. He wasn't on a high dose for me."
Jacobson insisted he had done nothing wrong, but he would stop prescribing controlled substances until the investigation is completed.
Separately Thursday, a physician accused of illegally selling prescriptions for oxycodone and driving to patients' homes to deliver the pills surrendered to face federal drug conspiracy charges.
Dr. Leonard Stambler made an initial court appearance in U.S. District Court in Central Islip and was ordered held without bail until a Monday hearing. His attorney, Gary Schoer, didn't enter a plea and declined to comment afterward on the charges.
The arrest comes amid a heightened awareness of prescription painkiller abuse. Laffer said at his sentencing last month to consecutive life prison terms that he hoped his case would lead authorities to examine the phenomenon of "doctor shopping."