KUCHING: The Marine Department will investigate the sinking of the Naga 7 drilling rig off Miri. "An investigation team has been set up by the Sarawak region marine department to find out the cause of the incident," the department said in a statement on Wednesday (May 5). The department confirmed receiving a report of the incident which occurred at about 2.45pm Monday (May 3), about 139 nautical miles from Miri. The Naga 7 jack-up rig was carrying out pre-loading works when one of its legs was said to have punctured through the seabed, causing it to list. The rig is owned by Velesto Energy Bhd and chartered by oil and gas company ConocoPhillips Sarawak Ltd.