A powerful House Republican has waded into the Drakes Bay Oyster Co. controversy by asking the Interior Department for copies of all the documents related to last year's decision not to renew the Marin County oyster farm's permit.

Rep. Doc Hastings, R-Wash., chairman of the House Natural Resources Committee, made the request in a letter to Interior Secretary Ken Salazar that revived allegations of scientific misconduct in the government's assessment of the oyster farm's impact on Drake's Estero in the Point Reyes National Seashore.

"Serious questions have been raised about the science used by the National Park Service to justify the closure of the oyster farm," Hastings said in a written statement.

Oyster farm operator Kevin Lunny said he appreciated Hastings' support, while Rep. Jared Huffman, D-San Rafael, whose district includes Marin County, said it reflected a Republican Party agenda to make public lands "available to oil and mining interests to exploit."

Huffman, one of six California Democrats on the resources committee, also said that Hastings' engagement in the oyster farm case was "a political witch hunt to embarrass the administration."

Hastings' letter gave Salazar until April 26 to submit a massive number of reports, emails and other documents related to the secretary's Nov. 29 decision that resulted in an order to close the farm, which harvests $1.5 million worth of oysters a year from the estero.

That order has been stayed by the 9th Circuit Court of Appeals in San Francisco, which has agreed to hear a lawsuit filed by Lunny on May 14. His suit contends that Salazar's decision was "arbitrary and capricious."

Hastings' letter Friday marked the second time in two months that federal lawmakers have taken up Lunny's cause.

In March, Sen. David Vitter, R-La., included a provision granting the oyster company a permit in a still-pending bill aimed at creating 2 million jobs and $2 trillion in federal taxes through commercial use of natural resources, including offshore oil drilling and approval of the Keystone XL pipeline.

Hastings' letter is "just starting the oversight process" and does not represent an official investigation, said Mallory Micetich, a spokeswoman for the House resources committee.

The Interior Department's response "will dictate how we play out the rest of it," she said.

A department spokeswoman said Tuesday she could not comment on pending litigation.

Lunny said he welcomed the committee's involvement in a case that has roiled west Marin County politics for years, prompting intervention by Sen. Dianne Feinstein in 2009.

Feinstein, who accused the park service of faulty science, wrote the legislation that gave Salazar sole discretion to renew the oyster farm's permit.

"No one should be afraid of an inquiry to see that the scientific process was respected," Lunny said, adding that Huffman should support President Barack Obama's call for scientific integrity in government decision-making.

"If the GOP leadership is interested in science, this would be a first," Huffman said.

Lunny asserted that the Park Service's environmental report, including a finding that oyster farm operations had impacted a harbor seal colony in the estero, was flawed.

The errors led to invalid conclusions about the impact of oyster farming in a document that is being cited in other cases, Lunny said. "That needs to be corrected," he said.

Opposing briefs in the legal case -- filed by National Park Service attorneys and Lunny's defense team -- also contest the science, but the legislative and judicial processes are separate.

Wilderness advocates, who want the oyster farm removed from the estero, criticized Hastings' interest in the matter.

Amy Trainer, executive director of the West Marin Environmental Action Committee, called the request for documents "a fishing expedition" aimed at challenging the legal basis for Salazar's decision.

Renewed allegations of scientific misconduct amount to "recycling a manufactured controversy," Trainer said.

Hastings' letter acknowledged that Salazar's decision "clarified that it was not based on scientific data that had been criticized as flawed."

Salazar said in his decision that it was "based on matters of law and policy." The environmental assessments "do not resolve all of the uncertainty surrounding the impacts of mariculture operations on Drakes Estero," he said.

You can reach Staff Writer Guy Kovner at 521-5457 or guy.kovner@pressdemocrat.com.