What was found
DURING CRUISE FLIGHT A CREW MEMBER REPORTED SEEING SMOKE IN THE CABIN FWD OF THE STRETCHER WITH A STRANGE SMELL IN THE CABIN. THE PILOT DID NOT WITNESS THIS SMOKE, BUT RETURNED TO BASE FOLLOWING A DISCUSSION WITH THE MEDICAL CREW. ONCE ON THE GND, THE PILOT COMMUNICATED VERBALLY WITH THE MECHANIC & IT WAS DETERMINED THE MOST LIKELY CAUSE TO BE FROM AN ENG WASH THE PREVIOUS DAY. THEY PERFORMED MULTIPLE GND RUNS FOLLOWING THIS EVENT & COULD NOT DUPLICATE THE ORIGINAL DISCREPANCY REPORTED BY THE MEDICAL CREW. THE ACFT WAS RETURNED TO SERVICE AT THIS TIME.