An Environmental Protection Agency ecologist helped native Alaskan tribes craft a petition to block a mine and then fled the country rather than testify about his role, according to a House Oversight Committee report.

The report comes after a prolonged fight over the Pebble Mine project site in the Bristol Bay region of Alaska. The mine has been the subject of scrutiny in Congress in recent months, including a House Science, Space and Technology Committee meeting Thursday morning.

Work on the project stalled before it could even begin. In May 2010, six Alaskan tribes submitted a request to the EPA for it to issue a rare pre-emptive veto to block Pebble Limited Partnership, the group looking to build the mine, from continuing.

The report says Phil North, an ecologist with the EPA, told a community newspaper in Alaska he wanted the EPA to use the pre-emptive veto as early as 2009. House Oversight Committee investigators asked in 2013 for North's communications and documents to see if he was working with the tribes, but North had illegally been using personal email to conduct official business and thus skirted the request.

And then North fled, the report said.

"North was unwilling to participate in a voluntary transcribed interview with committee staff, and his attorney was unwilling to accept a subpoena for testimony on his behalf," the report stated. "North then left the country and avoided service by the U.S. Marshals Service of a subpoena to be deposed by the committee. According to press reports, North was most recently in Australia."

North had a close relationship with the tribes and other anti-Pebble Mine groups who submitted the May 2010 petition for the pre-emptive veto. Communications turned up by the committee show North even edited the petition for the tribal groups a month before it was submitted.

Other communications turned up by the committee show EPA lawyers discussing how they could make sure communications about the pre-emptive veto could avoid Freedom of Information Act requests.

The findings are enough for the committee to charge collusion between the EPA and anti-mine groups, according to the report.

"Proof of collusion is in fact a basis to reconsider EPA's [pre-emptive] action against Pebble Mine," the report says. "EPA's actions with respect to Pebble Mine, and especially the conduct of Phil North, represent an unprecedented change in the agency's process for regulating resource and development projects."

The mine is a potentially lucrative site. The value of the copper, molybdenum and gold at the site could be worth $300 billion. In addition, the report estimates the mine would create thousands of jobs in Alaska and more than 10,000 in the rest of the country.

However, it could also cause damage to the waters near the mine.

According to the Bristol Bay Watershed Assessment, disposal of material from the mine in the Bristol Bay watershed would result in "unacceptable adverse effects on ecologically important streams, wetlands, lakes, and ponds and the fishery areas they support," the report stated.

Bristol Bay is home to one of the largest wild salmon populations in the world. That salmon population supports a $500 million commercial and sport fishing industry in the area, according to Trout Unlimited.

Proposed designs of the Pebble Mine would include one of the world's largest earthen dams and a 10-square mile containment pond to hold the wastewater from the mine. Trout Unlimited says any breach of that dam or that containment pond could severely damage the wild salmon population.

In a statement Thursday afternoon, the EPA emphasized it has not issued the pre-emptive veto that concerns the committee. It has proposed limits on allowable discharges into federal waters to protect fish in Bristol Bay.

Pebble LP has not submitted an application for a Clean Water Act permit to develop the mine but the agency has met "many times" with proponents and opponents of the mine, it said. One of the criticisms leveled by the committee was that the EPA has given short shrift to those in favor of building Pebble Mine.

"Congress provided EPA with the authority to use [the pre-emptive veto in] the Clean Water Act 'whenever,' including before or after permits have been applied for or issued," the agency said.