A Denver International Airport spokesperson said airport authorities have caught 16 people trying to sneak marijuana through security checkpoints. Reuters

Several rental car companies that serve Denver International Airport are reporting marijuana being passed off to their workers when renters return their vehicles.

According to Denver’s KCNC, rental car workers at DIA told the station that travelers are now using the agencies as a place to dispose of marijuana they can’t legally take out of Colorado.

Though out-of-state visitors can legally purchase weed in Colorado, marijuana is prohibited in DIA. Retail marijuana sales were first legalized in January. This has set off a wave of tourists traveling to the state to partake in the legal marijuana fest.

One car rental worker, whom the station did not identify, detailed that customers more often abandoned their weed on the weekends. A second added that the pot the worker is offered is typically thrown in the trash while another said it was instead given to supervisors to dispose of.

Stacey Stegman, a spokesperson for DIA, says that 16 people have been caught by airport authorities attempting to sneak marijuana through security checkpoints. Instead of citing the travelers, though, officials just ask them to throw the marijuana away.

Travelers' awareness about the airport's strict policy on marijuana has in turn prompted visitors to hand their weed off to rental car employees or simply leave it in the vehicle.

Most of the employees speaking with KCNC said that marijuana was “frequently” passed off to rental car workers. According to one worker, some renters will even attempt to tip with weed in lieu of cash.