COLUMBIA, Mo. -

Six people from the Columbia area have been arrested on federal drug-trafficking charges after an investigation by the U.S. Postal Inspection Service and Columbia Police revealed large amounts of marijuana being sent through U.S. mail.

U.S. Attorney's Office spokesman Don Ledsford confirmed to ABC 17 News that the federal complaints were unsealed yesterday.

ABC 17 News first reported the arrests of 22-year-old Joshua Dillick and 23-year-old Nicholas Kampe on March 6th.

Police found more than 6 pounds of marijuana, drug paraphernalia, $23,900 in cash at homes at 911 W. Ash Street and 4600 Fenimore in Columbia, where respectively Kampe and Dillick lived.

Both Kampe and Dillick were arrested on state charges for distribution and delivery of a controlled substance.

During their investigation, postal investigators and police determined that Kampe was dealing marijuana out of his home and had many other associates involved.

Investigators didn't immediately get a federal search warrant because they wanted to see if packages were being held inside the Kampe's residence or being picked up by a third party.

Postal investigators began tracking parcels coming through the mail from the San Francisco area to multiple Boone County residents.

One of the men arrested, Paden Poage, told police that approximately 40 pounds of marijuana were being shipped through the mail each week to Columbia by his former roommate.

Kampe's associate Zachary Heath told investigators he was accepting packages for Poage, and observed duffel bags at Poage's home containing thousands of dollars; one in particular contained $35,000.

Others charged in the investigation are Mona Halawaeh, Ryan Concannon, and Alex Thornton. No federal charges are filed against Joshua Dillick.

The six are charged with felony conspiracy to distribute and possession with intent to distribute a controlled substance, use of a telephone to commit or facilitate a felony of intent to distribute a controlled substance, and distribution of a controlled substance.

The affidavit from the United States Postal Inspection Service can be viewed here, or in the related content section of this page.