What was found
(CAN) SHORTLY AFTER T/O, THE PILOT NOTED A LOW TORQUE WARNING WHICH WAS FOLLOWED BY THE PROPELLER GOING INTO FEATHER. THE PILOT SECURED CONTROL OF THE A/C AND THEN HE SELECTED THE "MAX. CONTINUOUS" SWITCH ON THE POWER SELECTION PANEL. THE ENGINE POWER WAS RESTORED AND THE A/C WAS FLOWN BACK TO THE DEPARTURE AIRPORT WHERE AN UNEVENTFUL LANDING TOOK PLACE. TROUBLESHOOTING IS ON-GOING.