The DeKalb County Sheriff's Office tells TMZ Bret was onboard one of buses when cops made the stop at around 11:30 PM. K9s found the pot. One of the buses -- not the one Bret was on -- had Schedule II controlled substances inside, and cops tells us they're illegal drugs.
Citations were issued but no arrests were made. The case is being forwarded to DeKalb prosecutors.
Michaels' rep gave us the following statement:
"Two of Bret’s tour buses were pulled over late last night. Officers on the scene claimed there were no trailer tag lights. No arrests were made. Mr. Michaels allowed an open search of the buses and everything was handled in a professional manner."