Regional Jet 900 (CRJ900)
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Deviation / Discrepancy - Procedural Weight And Balance; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural FAR
General None Reported / Taken
Human Factors
I was assigned to conduct a repo flight on a CRJ 900 which was coming out of maintenance.  Myself and the First Officer met with Maintenance staff on the maintenance ramp adjacent to taxiway A.  I spoke with several maintenance personal who confirmed there was nothing in cargo and that there was no need for a CLR (Cargo Load Report).  It was unknown to the flight crew at the time as to why the aircraft was being repositioned.  The flight was completed without incident.  Upon arrival to ZZZ1; I spoke with the crew that was operating the return flight to ZZZ.  It was ascertained that the original aircraft they were to use Aircraft Y  had a malfunction with the emergency lights.  At this point; we were notified by scheduling that we would be repositioning Aircraft Y back to ZZZ once it received repairs.  I happened to notice the Maintenance personnel in ZZZ1 was removing something from the cargo hold on Aircraft X.  I asked personnel about this and they stated that the 2 emergency light batteries that had to be replaced on Aircraft Y were on Aircraft X when we flew from ZZZ.  At this point I realized that we had cargo in the hold that we weren't aware of.  The total weight was 12 pounds.  Observed when arrived in ZZZ1. Maintenance not notifying the crew of cargo.  Not physically checking the cargo myself. In the future I plan on always checking the cargo hold myself if it is reported as empty.  'Trust but verify' would be a good lesson to take from this incident.  It would be helpful if Maintenance Control developed reporting procedures when parts are being transported on repo aircraft that would notify the crew to help mitigate inadvertent errors like this in the future.
CRJ Captain reported inadvertently transporting Dangerous Goods.