As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT DEPARTED LAND BASE FOR OFFSHORE LOCATION. ENGINE OIL PRESSURE LIGHT FLICKERED. RETURNED TO SHORE BASE AND LANDED WITHOUT INCIDENT. OIL PRESSURE HAD DROPPED TO ZERO UPON LANDING. FOUND ENGINE OIL TANK EMPTY. SIGNS OF OIL GOING OUT THE EXHAUST. AS-350 IPC, CHAPTER 71.10.11, ITEM 20B.