PAWHUSKA, Oklahoma - Pawhuska Police take four men into custody, accused of transporting thousands of pounds of what officers believe is marijuana.

The attorney for two of the men told News On 6 they'd been charged with aggravated trafficking. Pawhuska Police pulled the semi-truck over early Wednesday morning for running a red light, but officers quickly noticed something else.

"You could smell the strong odor of marijuana," Pawhuska Assistant Police Chief Alton Horne said.

Police said two men were inside the truck and two men were inside an escort mini-van as security. The men showed officers a bill that detailed their cargo as hemp.

"It was just a simple bill," Chief Rex Wikel said. "Anybody could generate it on a computer."

The bill stated the men were transporting 18,000 pounds of hemp from Kentucky to Colorado, but police said something felt wrong.

"It just didn't seem right," Horne said. "You've got that gut instinct like, there's something going on here."

Officers said the product field-tested positive for marijuana, so they called in backup, including the DEA.

"Come together and work as a team," Horne said. "If we didn't, we just couldn't handle this."

Law enforcement said the recent legalization of medicinal marijuana makes things more complicated.

"It's a large gray area with everybody right now," Osage County Sheriff Eddie Virden said. "What's a legal load of marijuana, and what's an illegal load?"

The Oklahoma Bureau of Narcotics said to transport marijuana legally, you have to have an Oklahoma Medical Marijuana Transport License. But the men's attorney said they were transporting hemp and had fully researched Oklahoma laws to make sure they were doing everything properly.

Pawhuska Police said they'll test the product in all the boxes to see exactly what they found.