More than a dozen current and former Boeing (BA) employees were arrested at the jet maker’s plant outside of Philadelphia Thursday morning in a prescription drug raid, the Department of Justice said.

Agents from the FBI and Drug Enforcement Administration uncovered an illegal distribution ring of prescription drugs at the Ridley Park, Pa.-based factory, leading to indictments against 23 individuals.

The plant, which has about 5,400 employees, manufactures aircraft including the H-47 Chinook helicopter and V-22 Osprey. The group is part of Boeing's Defense, Space and Security unit.

Boeing had brought its suspicions of drug activity to federal law enforcement and the Justice Department said it has cooperated fully with the long-term investigation.

In a statement released Thursday afternoon, Boeing commended the U.S. agencies for their “rigorous and thorough investigation,” and said it took steps to “ensure the safety of its employees and the absolute integrity and quality” of its products.

In addition to the indictments, 14 other defendants are being charged with attempted possession, a misdemeanor, of the various drugs, including Actiq, Oxycontin, Xanax and Suboxone, being sold by their coworkers.

The DOJ alleges that the defendants either sold a controlled substance to an FBI cooperator or bought what was believed to be a controlled substance from the cooperator.

The raid comes amid growing concerns over the illegitimate sale of counterfeit prescription drugs. Worldwide sales of counterfeit medicines were estimated to exceed $75 billion last year, an increase of 90% since 2005.

“Drug abuse and the illegal sale and purchase of controlled substances are serious criminal problems in the U.S. today, and those who engage in the sale and distribution of pharmaceutical drugs will be targeted,” said FBI Special Agent-in-Charge George Venizelos.

“The abuse of prescription narcotic drugs can be as dangerous and devastating as the use of illegal drugs,” he said.

Law enforcement has ramped up investigations into counterfeit drugs, with the U.S. Department of Homeland Security seizing 170% more illegal pharmaceuticals products last year than in 2005.

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