Drug Enforcement Administration agents executed a search warrant at a Sherman doctor’s office Friday and collected records related to a doctor’s prescription writing, authorities say.

“It’s an ongoing investigation right now, and it has to do with his prescription writing of pain medication,” DEA Special Agent Elaine Cesare said.

The agents searched Diamondback Pain and Wellness Center at 500 E. Peyton St., which is operated by Dr. Howard Gregg Diamond. Cesare said the investigation, led by the DEA Dallas Field Division, has been ongoing for several months, and investigators had enough probable cause to obtain a search warrant.

“There was enough of the investigation that was able to get the diversion investigator a search warrant to go look at records of Dr. Diamond,” Cesare said.

Cesare said no arrests have been made, and Diamond was not taken into custody. On the same day, agents searched Diamond’s facility in Paris as well. Cesare said only records were collected from these locations.

Diamond did not return calls placed to his office seeking comment Monday. Cesare referenced a Facebook post by Dr. Diamond as reflecting a reason why he’s being investigated. On April 16, Diamond posted on his practice’s page a statement recognizing that local pharmacies stopped filling prescriptions for his patients.

“As many of you might know, for reasons that have not been discussed with me, most of the pharmacies in my practice region, Sherman and Paris Texas have stopped filling prescriptions for my patients,” Diamond said in the post. “This is an unexplained circumstance that is out of my control, and inconsistent with the medical welfare of my patients.”

The post goes on to state that Diamond was working to restore treatment to his patients, but did not have an answer for when that would occur.

“I realize that these actions of the pharmacies that have stopped filling my prescriptions for my patients is having serious and negative impact in your lives and I have no power or control to change that today,” Diamond said in the post.

He then asked his patients to show support by emailing a statement outlining how his treatment has affected them. He also asks that they include details of the pharmacies that would not fill the prescriptions, and the reasons they provided for that action.

According to Texas Medical Board online records, Diamond graduated from medical school in 1987, and was issued his medical license in 1988. The records show the board took action in August 2015 after it found Diamond “failed to maintain adequate medical records documenting his care and treatment of chronic pain patients.” The document noted that while a number of the records they reviewed were lacking in details, Diamond’s “prescribing was appropriate and his rationale was well-considered.”

As a result of the board’s findings, Diamond entered into a nondisciplinary remedial plan, which required him to complete eight hours of continuing medical education in medical record keeping. The remedial plan ended in September 2016 when Diamond completed the requirements.