Workers found three tiny holes in a fuel tank where a possible leak of jet fuel was detected in January, the Navy said Thursday.

The holes are so small they’re not visible to the naked eye, Navy Region Hawaii said in a news release. They were discovered Wednesday and Thursday during testing to determine whether air could flow through the tank wall. The ability of air to escape indicates liquid may be able to leak through as well.

The holes may be the reason 27,000 gallons of jet fuel was lost, said Capt. Mike Williamson, chief engineer for Navy Region Hawaii.

Gary Gill, the state Department of Health’s deputy director for the environment, said there should now be no doubt in anyone’s mind that some fuel was lost from the tank.

"The smoking guns have been found," Gill said.

Inspections of the tank will continue at least through the end of the month, said Navy Region Hawaii spokesman Tom Clements.

The Navy has 20 large cylindrical fuel tanks at Red Hill near Pearl Harbor that store fuel for ships and aircraft. Each tank is large enough to hold Honolulu’s Aloha Tower.

Gill said nearby Board of Water Supply wells — each about a mile away from the tanks to the northwest and south — don’t show any signs of petroleum contamination.

Each of the 20 tanks has leaked fuel over the past 70 years, Gill said. Petroleum-contaminated rock has been found under 19 of the tanks, while Navy records indicate the remaining one tank leaked at some point.

Further, the department knows the groundwater immediately beneath the tanks has been contaminated by petroleum.

"We don’t know how far the contamination plume beneath Red Hill has traveled and we don’t know in what directions it may have traveled," Gill said.

The department is working with the Navy to create additional monitoring wells to identify where the contamination may be spreading, he said. The department is also working with the Navy to clean up the fuel that spilled.

Gill said the department will work with the Navy to ensure the best technology is used to prevent additional spills, and that any future spills be immediately detected and measured.