EL JEBEL, Colo. (CBS4) – Someone stole pain killers from a Western Colorado fire station and the chief says it may have been an inside job.

The chief said someone stole a “significant amount” of drugs from the Basalt Fire Department’s main station in El Jebel, near Aspen.

The expired pain killers were being stored in an electronic vault awaiting disposal. The vault shows no sign of forced entry.

None of the employees with access tested positive for the stolen drugs.

Federal and state agencies have joined the investigation.

(credit: CBS)