The Navy confirmed more tiny holes in a leaking storage tank in Red Hill that appears to be a cause of the release of an estimated 27,000 gallons of jet fuel in January.

On Saturday, Navy officials said in a news release that 12 more tiny holes were confirmed in the empty Tank 5 at the Red Hill Bulk Fuel Storage Facility.

The Navy previously announced that three holes were confirmed during testing of the tank on June 16. Officials used a vacuum box to verify that air could flow through the tank wall.

The holes were found in areas that had recently undergone welding repairs.

"We’ve identified a cause of the fuel release from Tank 5 by visual inspection of the interior of the tank and follow-up non-destructive testing of anomalies identified during visual inspection," said Capt. Mike Williamson, Chief Engineer for Navy Region Hawaii, in the news release. "We will consult with our experts and determine if the combination of these defects could account for a loss of up to 27,000 gallons of fuel."

The Navy said it will begin testing the pipes that lead to and from Tank 5 by testing the pressure of the pipes and checking for a decreases in pressure that would indicate leaks.

Water wells at the nearby Halawa shaft and Moanalua shaft provide about 25 percent of the drinking water for urban Honolulu, but the Board of Water Supply has found no signs of contamination in the water supply around Red Hill,

During the early 1940s some 20 tanks were built below ground in Red Hill to store fuel for ships and airplanes.

Each of the 20 tanks is 250 feet tall, 100 feet in diameter and can hold up to 12.5 million gallons of fuel.