What was found
(CAN) DURING REVENUE FLIGHT, ON DESCENT CREW NOTICED SMOKE IN CABIN. SMOKE DISAPPEARED AS RT CABIN BLEED WAS SELECTED OFF. PROBLEM RESURFACED ON SECOND FLIGHT LEG BACK TO BASE AND RT CABIN BLEED WAS DESELECTED AGAIN AND FLIGHT COMPLETED UNEVENTFULLY. ENGINE RUNS FINE ON GROUND, NOTHING ABNORMAL NOTED. OIL LEVEL IS NORMAL. TROUBLESHOOTING ONGOING.