When Republicans took control of the Natural Resources Committee at the beginning of the year, they established an unusual policy: All witnesses are not created equal.

House rules require witnesses who testify before committees to first submit their credentials, generally a résumé and a list of government grants and contracts they hold.

But the GOP leaders of the Natural Resources Committee created a series of additional requirements for witnesses that represent nonprofit organizations. In addition to the basic background documents, nonprofit groups are required to disclose all lawsuits they have filed against the federal government for the past four years, any foreign donations the group has received over the same period, and three years of the group’s tax returns.

The rules create an odd imbalance in the disclosure packets of various witnesses.

On Sept. 21, the full committee held a hearing on oil drilling in the Arctic National Wildlife Refuge, inviting truck driver Carey Hall, star of the History Channel adventure show “Ice Road Truckers,” to testify. Hall submitted a four-page “Truth in Testimony” disclosure form, indicating that he was appearing as a representative of Carlile Transportation Systems, the Alaska-based trucking company he works for.

Hall did not have to provide any information about federal grants or contracts the company may have won, and he was not asked to provide any information about the company’s finances.

During his testimony, he volunteered that Carlile has “more than 600 employees” moving freight “all over the United States” and specializing in “movement of goods and equipment specifically for the oil and gas industry.” A 2010 report in the industry publication Treasury & Risk referred to Carlile as “a $135 million trucking and logistics company with 650 employees. It has offices in five states and Canada, and its revenue has doubled in the past seven years.” But those details were not disclosed at the hearing, where Hall emphasized the importance of opening ANWR to oil development to increase domestic oil supply and to boost “freight loads” for truckers in Alaska.

Sitting at the table with Hall was Gene Karpinski, president of the League of Conservation Voters, who was required to submit more than 100 pages of tax records and other materials.

The requirements for expanded disclosure by nonprofits are not spelled out in the committee’s rules, which were approved on a bipartisan basis at the beginning of the 112th Congress. Those rules say only that “all witnesses shall be required to submit with their testimony a resume or other statement describing their education, employment, professional affiliations and other background information pertinent to their testimony.”

The enhanced requirements are included in a disclosure form the committee provides to witnesses, which has a separate section with more detailed requirements for “witnesses representing organizations.”

Roll Call could not identify any other House committee that requires such detailed disclosures of witnesses or that differentiates its disclosure requirements based on who the witness represents.

In November, ranking member Ed Markey (D-Mass.) complained in a letter to Chairman Doc Hastings (R-Wash.) that the disclosure requirements “are onerous and result in disparate treatment of not-for-profit organizations.” Markey wrote that “at best, these requirements evidence purposeful, disparate treatment of certain classes of witnesses based on an apparent bias against not-for-profit organizations; at worst these requirements amount to selective witness intimidation.” Markey also said the disclosure form was not approved by committee Democrats.

But Hastings’ staff says Markey is missing the point.

“I think it is bordering on paranoia on behalf of the Democrats to think that this is meant to have a chilling effect or any kind of witness intimidation,” majority spokesman Spencer Pederson said.

The materials the committee is requesting “are things that are already publicly disclosed but not always readily available for members to access,” Pederson said. For instance, Pederson noted that while corporate earnings for publicly traded companies are available through the Securities and Exchange Commission’s EDGAR database, “there isn’t an easily available government database for 990 forms” — the tax forms filed by nonprofits — “so when those organizations come before the committee we simply ask them to provide them to the committee.”

However, a search of the EDGAR database turns up no records for Carlile Transportation.

The enhanced disclosure requirements are not limited to environmental groups or other organizations that are likely to be ideologically opposed to the Republican majority’s agenda. The American Petroleum Institute filed a 106-page disclosure form for a Nov. 18 hearing on domestic energy resources, and the American Sheep Industry Association filed 70 pages of tax forms for a hearing about grazing and other commercial activity on public lands.

Pederson also said it is curious that Democrats are opposing transparency and waited until November to complain about disclosure requirements that have been in effect all year.

But Eben Burnham-Snyder, a spokesmen for the panel’s Democrats, said that since the majority is responsible for sending invitations to witnesses, the minority didn’t even know Republicans were requiring this information until the summer, when some witnesses began to complain. “They didn’t tell us it was happening, and when we realized it, we objected,” Burnham-Snyder said. “They told us they were going to do it anyway.”

Jay Tutchton, general counsel of WildEarth Guardians, said the 118 pages his group filed when he testified before the committee last week “was an administrative burden for a smaller organization like ours.” Tutchton said his group got the invitation to testify a week before the hearing and had a staff member spend an entire day assembling the disclosure materials, while the organization was also scrambling to prepare testimony for the hearing.

WildEarth is in favor of transparency, Tutchton said, but “These particular disclosures don’t really seem designed to inquire into the conflict-of-interest type [of] thing. … But to fish around and see if there is something there to embarrass you with.”