An historic building dating back to the early 19th century has been gutted in a major fire.
Gardaí and Military Police today launched a joint investigation into the inferno, which destroyed part of a naval base at Cork Harbour.
At its height eight units of Cork city and county fire brigades tackled the blaze, which broke out around 8.30pm yesterday.
Fire fighters battled throughout the night against strong winds to control the flames and stop the fire spreading to a second landmark building at Haulbowline, Co Cork.
Crews were still at the scene today to ensure high winds do not re-ignite the smouldering remains.
The building, one in a series of six warehouses, was built between 1810 - 1815 and houses the UCC Coastal Marine Resource Centre, offices and store rooms. It had been undergoing extensive renovations.
A former British Army base, Haulbowline is now the headquarters of the Irish Navy. The island is linked by a causeway to the mainland at Ringaskiddy.
Fire fighters said the flames were already rising through the roof when they arrived at the scene.
A civilian tug boat from Cobh and naval service personnel joined the eight crews at the scene, which included five from the county and three from the city and consisted of five pumps, two hydraulic platforms and a special service vehicle.
No naval vessels had to be moved from the harbour during the incident.