Enbridge says up to 1,500 barrels of oil may have leaked from its pipeline in the Northwest Territories last month, much higher than the company's initial estimate of four barrels.

Company spokesperson Gina Jordan said late Monday that the volume of oil that spilled from its Norman Wells pipeline "could range from a minimum of 700 barrels to a maximum of 1,500 barrels."

"Based on its current analysis, Enbridge anticipates the probability that the maximum volume would be exceeded to be low," Jordan wrote in an email.

Enbridge had originally reported that just four barrels of oil leaked on May 9 from the pipeline, located about 50 kilometres south of the community of Wrigley, N.W.T.

But on Friday, Jordan said Enbridge cleanup crews had removed about 90 barrels of oil from the spill site. That figure was updated to 100 barrels on Monday.

Chief wants inquiry

"It just doesn't surprise me," Wrigley Chief Tim Lennie, who was among the first people to discover the leak, told CBC News late Monday.

Lennie said while people in Wrigley, a community of over 100, had suspected it was a larger spill all along, the latest news is still hard to digest.

"It's anger, it's frustration. I'm quite certain with this news, there will be more questions," he said. "There needs to be an inquiry on this, I feel now."

Jordan said third-party experts are trying to more accurately determine subsurface contamination, and once that is complete a revised estimate of the size of the release can be determined.

"Our original four barrel estimate was based on oil collected at the surface and did not take into account the subsurface impacts, which were believed to be not significantly different," Jordan wrote in the email.

"The increase in subsurface oil was discovered during the ongoing environmental site assessment, which includes subsurface analysis and is standard practice for all releases."

River not affected, says company

Jordan maintained that the oil leak has had no impact on the nearby Willowlake River.

But Lennie said he has heard otherwise from people living in the area.

"[The company] said there has been no impact at all on anything, you know, to date. I mean, it's just been ridiculous," he said.

The National Energy Board says it has no reason to doubt the information it has received from Enbridge.

"Obviously, we rely on the company to report accurately," said Ken Colosimo, an environment and emergency preparedness specialist with the federal board.

"We also rely on the certified consultants that they use and the labratory analysis that we get."

Colosimo said the NEB went to the spill site after it was first reported. Officials will return to the area soon for an inspection, he added.

The Norman Wells pipeline was back up and running on May 20, after repairs were made. Enbridge says the cause of the pipeline leak remains under investigation.

With files from The Canadian Press