With environmental groups mounting a worldwide campaign against the expansion of oil palm plantations, Cargill is relying on Conservation International (CI), a Washington, D.C.,- based environmental group, as its ecological guide in Papua New Guinea. Two issues stand out: water contamination and protection of the world's largest butterfly, the endangered Queen Alexandra's Birdwing, a biological wonder boasting a one-foot wingspan that lives near Cargill's Oro Province plantation.

Tainted water worries villagers, in part due to the generally widespread use by oil palm plantations of paraquat, a chemical banned in the European Union and strictly controlled in the United States. Cargill said last week that it stopped using paraquat in Papua New Guinea in September.

But Conservation International hasn't tested rivers or streams in the two years since it was hired for $1.5 million, said David Mitchell, its director in Papua New Guinea. It did test an ocean reef, the results of which are confidential, Mitchell said.

Other testers have found problems. A 2006 test by Australian researchers in streams near Cargill's Oro Province mill found residues, which, though not toxic, contain acidic greases that can kill off plant and fish life. The researchers lacked equipment to test for chemical runoff.

Mitchell characterized the test as out of date, and added that it's the government's responsibility to monitor the water. "That's the watchdog of the industry."

Still, Cargill trumpets CI and its research in a recent company magazine. "There have been charges that the palm industry is polluting the ocean," Mitchell is quoted as saying, "but no evidence has been presented."

Mitchell, asked about the quote, said he was unaware that Cargill had used it, but stood by the statement.

More than a third of Cargill's payment to CI has gone to staff, rent, travel and membership in a palm oil industry group, said a CI spokeswoman. Environmental work, including the reef test and a survey to count butterflies, cost $201,345. Nearly twice that was spent building a database of endangered animals and protected lands.

Such relationships strike some critics as little more than green-washing, allowing corporations to hide behind environmental groups. "The companies get a lot more out of these arrangements than the endangered species," said Christine MacDonald, an author and former CI staff member.

CI said its Cargill deal is typical of the "corporate engagement" it has with large companies. It comes down to "results," said John Buchanan, CI's senior director of business practices. "That's what CI's credibility ultimately relies on."

Separate from Cargill, CI's results in Papua New Guinea came under fire two years ago in a project funded in part by the United Nations. "Project management by CI has been extremely poor, indeed negligent," a U.N. report said. It concluded CI misspent $821,000 to $1.2 million.

A CI spokesman dismissed the U.N. report as political.

Cargill says it has "engaged" CI to "assist us" in water studies.

The two were negotiating extending their relationship two more years, a CI spokeswoman said.