What was found
(CAN) DURING CLIMB, THE CREW RECEIVED A LOW OIL PRESSURE WARNING WITH THE OIL PRESSURE READING 0 ON NR 1 ENGINE. ENGINE WAS SHUTDOWN AND SECURED AND THE ACFT RETURNED TO THE DEPARTURE AIRPORT WHERE AND UNEVENTFUL SINGLE ENGINE LANDING WAS ACCOMPLISHED. POST FLIGHT INSPECTION SHOWED NO LEAKS ON COWLING OR TAILPIPE. OIL TANK SIGHT GLASS LEVEL WAS GOOD. AFTER 1 HOUR, THE ENGINE WAS STARTED AND THE OIL PRESSURE WAS NORMAL. OPERATOR WAS UNABLE TO DUPLICATE ISSUE AND ACFT RETURNED TO HOME BASE.