Eleven suspects were arrested this week after they allegedly participated in a UPS drug trafficking ring out of Tucson, Arizona, for nearly a decade.

The arrests followed a two-year investigation into a group of United Parcel Service (UPS) employees who were reportedly smuggling and shipping illicit drugs and counterfeit vaping oils all over the U.S., according to KOLD.

Agents with the Department of Homeland Security (DHS) said “the suspects moved thousands of pounds of marijuana and other drugs into the U.S. from Mexico each week using the company’s standard cardboard boxes, bypassing security measures,” Fox News reported.

DHS said its agents, along with officials from the Tuscon Police Department, also discovered that the suspects used techniques to “defeat internal measures and law enforcement efforts to identify and intercept parcels containing contraband,” according to AJC.com.

The alleged ringleader, Mario Barcelo, who worked as a dispatch supervisor for UPS for 20 years, was arrested November 13. Prosecutors said the 49-year-old used his position at the Tucson distribution facility to direct the drug shipments and make sure they arrived at their intended destinations.

The Fox News report continued:

Aside from Barcelo, UPS supervisor Gary Love and drivers Michael Castro and Thomas Mendoza are charged with money laundering, drug possession and drug distribution. Seven others are facing charges on shipping drugs and operating stash houses. Raul Garcia Cordova, 47, faces more than a dozen charges. A police raid at his home turned up 50,000 counterfeit vaping pens, a Chevrolet Corvette and a Range Rover.

In a recent statement, the Sandy Springs-based UPS said it was “aware of the law enforcement actions involving employees,” adding that “we cooperate fully with law enforcement professionals and will continue to provide information as needed.”

November 20, DHS Acting Secretary Chad Wolf tweeted a message to those involved in transnational criminal activity.

“You can not outrun our agents. You cannot hide from our reach. We will seek you out. We will track you down,” he wrote, adding “And we will destroy your operations and the death machine you are attempting to operate.”