James and Chico DeBarge were arrested last week for drug possession during a traffic stop in Los Angeles — and cops say they found possible fentanyl and meth on the 80s singing sensations.

Our law enforcement sources tell us … James and Chico were busted on the night of August 27 in Burbank, CA, after police pulled them over for traffic violations.

We’re told James was driving a Chevy Tahoe that was towing a Nissan SUV with Chico sitting inside. Our sources say the SUVs did not have license plates and the siblings were not wearing seatbelts … both of which would be traffic violations.

We’re told, during the stop, police found the brothers in possession of “suspected fentanyl and suspected methamphetamine.”

James and Chico were arrested for possession of a controlled substance, and cops say Chico also had an outstanding warrant … although it’s not clear for what. NBC4 was the first to report on the news of their arrests.

The DeBarge brothers come from a large family of musicians and were popular throughout the ’80s and ’90s with hits such as “Rhythm of the Night” and “I Like It.” Over the years, Chico has been very open about his drug issues and even previously served time on narcotics charges.