Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Security
General Maintenance Action
Procedure; Human Factors
After my Dispatcher disconnected the tow bar; the pilot informed him that a passenger believed that their last minute checked carry on was loaded with a lithium ion battery that they failed to remove prior to boarding. We returned the aircraft to the gate to retrieve the bag. Once parked; my crew pulled the bag off the aircraft; scanned to offload it; and were holding it planeside. While I was helping my pit guy close up the FWD pit; Supervisor took the questionable bag from the planeside; and breached security by not only taking the bag upstairs and crossing the threshold of the secured area; but also leaving it unattended in the jetbridge. When I realized what had happened; and confronted [supervisor] about the breach in FAA protocol; he said he knew that he was not supposed to bring the bag up; but did so anyway.
Ground employee reported removing passenger luggage from cargo due to Hazmat restriction. Reporter also noted FAA security breach by leaving baggage in unattended on the jetbridge.