DENVER—A Colombian national is returning to federal court in Denver on a weapons charge after his arrest during raids on medical marijuana businesses.

A preliminary hearing is scheduled Thursday for 49-year-old Hector Diaz on one count of possession of a firearm while in the U.S. on a business or tourism visa.

Diaz has not entered a plea. He is expected to be released on bond sometime after Thursday's hearing.

Diaz is the only person reported to have been arrested during the Nov. 21 raids on more than a dozen sites, most of them related to medical marijuana businesses in Denver and Boulder.

Prosecutors have not said whether he is linked to the pot investigation, nor have they disclosed the reasons for the raids.