BOSTON (CBS) – A doctor on the Cape has been indicted for illegally prescribing oxycodone and defrauding the state’s Medicaid program.

Dr. Mohammad Nassery, 63, who practiced at Ariana Pediatric Neurology in Hyannis, was indicted Friday by a grand jury in Barnstable Superior Court on 11 counts of writing illegal prescriptions, 9 counts of making false Medicaid claims and one count of larceny over $250.

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Massachusetts Attorney General Maura Healey announced the indictment Monday.

She claimed Nassery wrote prescriptions he knew were “medically unnecessary” and provided “powerful painkillers to people with documented substance abuse problems.”

Healey said medical records showed Nassery continued to prescribe oxycodone and Percocet to patients “despite their documented substance abuse, and after learning that some patients were concurrently enrolled in substance abuse treatment programs or were receiving opioids from other prescribers.”

Dr. Mohammad Nassery (WBZ-TV)

Dr. Mohammad Nassery (WBZ-TV)

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The attorney general said each illegal prescription Nassery wrote “allegedly caused pharmacies to unwittingly falsely bill MassHealth for the medication.”

Investigators claim Nassery would continue to prescribe oxycodone and other similar drugs, even though some patients were not getting required urine tests or those tests showed that patients were not taking the medications as directed.

According to the indictment, Nassery also falsely billed MassHealth by charging for simple office visits using a billing code reserved for more complex and expensive medical exams.

As a result of the indictment, Healey said Nassery has agreed to no longer practice medicine.

“(We) are proactively working to ensure that Dr. Nassery’s patients are notified about this case and referred for proper care and treatment by other medical professionals,” Healey said in a statement.

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According to her office, four out of five heroin users in Massachusetts began with prescription drugs.