NEWINGTON, N.H. — A New Hampshire company that reported a fuel oil leak into the Piscataqua River said today it believes the amount was far less than initially thought.

Sprague Energy in Newington said a small hole in a pipeline that bridges parts of a larger fuel loading pipe led to the fuel leak Thursday.

The total capacity of the pipeline is 4,700 gallons. However, “early indications are that the amount of oil that escaped is estimated to be substantially less,” the company said in a statement. Sprague did not specify an amount.

Company spokesman James Therriault described the problem as a “pinhole” that developed in the pipeline, resulting in a “spray.”

“The fuel that was in there was under some pressure and it just sprayed out the line,” he said. “We do regular detection rounds where somebody walks the entire grounds of the terminal. Somebody had last walked down there at 9 p.m.” The leak was reported by a fisherman at about 11:15 p.m. “So we know it’s somewhere in that window that it developed,” he said. Earlier reports that a cargo boat was unloading fuel into the plant were incorrect.

Mike Wimsatt, director of the waste management division for the Department of Environmental Services, agreed that the leakage is probably less than originally estimated. He said some areas of sheen can still be seen and that it could take several days to decontaminate the area.

“At this point, it does appear to be a small amount,” he said. “We don’t have serious concerns about impacts to the environment or wildlife at this point.” He said there has not been a record of any compliance problems involving Sprague.

Crews are working to recover the oil. The majority of the spill is believed to have been contained in the company’s dock area. The U.S. Coast Guard, the DES and local agencies were assisting with the cleanup.

The DES, as a precaution, decided to close some shellfish beds that had been open to commercial harvesting, Wimsatt said.

The oil is No. 6 oil, an industrial fuel used to power plants and ship boilers.

The river borders Maine on its northern bank and New Hampshire on its southern bank. It empties into the Atlantic Ocean east of Portsmouth, N.H., and is known for having some of the fastest currents on the East Coast.