An “elite” group of liberal “millionaires and billionaires” is pumping money into an elaborate network of environmental groups to influence EPA policies, even using “shady” donations from a foreign company to fund their efforts, according to a lengthy report by Senate Republicans.

The 92-page report was released Wednesday by Republicans on the Senate Committee on Environment and Public Works. The study endeavors to expose an alleged “far-left environmental machine” that Republicans say exerts “tremendous sway” over policies that hurt the economy.

"There is an unbelievable amount of money behind the environmental movement and far too much collusion between far-left environmental groups and the Obama EPA. This report really gets to the core of tracking the money and exposing the collusion," Sen. David Vitter, R-La., top Republican on the committee, said in a statement.

The report on the so-called “billionaire’s club” highlights a host of individuals and foundations and nonprofit groups -- some of which benefit from favorable tax treatment -- that work together on environmental causes. According to the report, well-known advocacy groups like the Sierra Club are the face of the movement, but provide “cover” for “secretive foundations” that provide the money, sometimes through intermediaries.

The report highlights about a dozen of these private foundations, backed by members of the “billionaire’s club,” that the authors say hold sway over the movement.

They include the Rockefeller Brothers Fund (run by members of the famed Rockefeller family); the Schmidt Family Foundation (launched by Google executive Eric Schmidt and his wife); and the Heinz Family Foundation (led in part by Teresa Heinz Kerry, wife of Secretary of State John Kerry).

Several of these foundations have been around for a long time, and fund a variety of causes, not limited to the environment. The Rockefeller Brothers Fund, for instance, was founded in 1940 and, aside from environmental causes, focuses on democracy promotion and conflict prevention abroad.

The environmental left also does not have a monopoly on well-heeled donors and foundations. Pro-oil and gas interests likewise have a robust funding network.

The report, though, makes particular note of the Sea Change Foundation, which is led by hedge fund power couple Nathaniel Simons and Laura Baxter-Simons -- and receives millions from foreign company Klein Ltd., based in Bermuda. Sea Change then donates that money to a variety of other environmental groups.

The report says the San Francisco-based group was the sixth largest donor to environmental issues in 2011 – giving over $43 million in grants -- but little public information about the group is available. Its website includes only a logo and a brief mission statement. And the donations from Klein Ltd. are anonymous, which the report calls problematic.

Further, the report alleges that the environmental groups have forged deep ties with the Obama EPA, and notes that top officials in the agency come from groups like the National Audubon Society, Natural Resources Defense Council and divisions of the Sierra Club.

Nathaniel Simons and the foundations cited above have not returned requests for comment from FoxNews.com.

Dan Epstein, director of the conservative Cause of Action, said in a statement that the report also speaks to a problem of “fiscal sponsorship” – where charities effectively sell nonprofit status to others, in turn receiving charitable donations for another group.

“Cause of Action has asked the IRS to take simple steps to define the rules for fiscal sponsorship, but they refused to do so, protecting their political friends, while targeting their political enemies,” Epstein said.