To help the tribal economy near the Amazon rainforest, they agreed to pay the Indians to cultivate some medicinal plants.

The hope was to identify more of Brazil's vast but largely unknown biodiversity, and find cheap treatments for dozens of ills afflicting the world. But an employee at the federal Indian affairs agency accused them of biological piracy and got a court injunction halting their project.

Seven years later, they are still stuck in legal limbo, waiting for Brazil's government to pass laws giving scientists access to plants on Indian reservations and in national forests, and defining how researchers should share any profits with poor local communities.

"This is the biggest imbroglio scientists are facing in Brazil," Carlini told Reuters.

People who oppose research on Indian lands, many of them in the government, worry scientists will hand over findings to foreign pharmaceutical companies, allowing them to make huge profits from unique local cultures in the Amazon. Indians, meanwhile, resent the paternalistic nature of the state that obstructs their wishes to collaborate with researchers.

Stopping biopiracy -- which happens when scientists or companies fail to pay local groups or governments in exchange for their plants or knowledge -- will be on the agenda at a United Nations conference on biodiversity in Curitiba, Brazil from March 20-31.

Biopiracy must stop, most people agree. But sharing benefits is complicated. Anthropologists worry cash payments could erode Indian cultures. Economists wonder if payments should be made to a municipal, state or federal authority.

Scientists are anxious for change. Brazil has an estimated 60,000 plant species, but less than half are defined in textbooks. Discoveries could generate business.

TRUCKS AND SATELLITE TV

Even when companies risk the uncertain legal environment and cobble together benefit-sharing plans with poor communities, they are often caught in ethical dilemmas.

Experiments by companies that consider themselves socially or environmentally aware have had mixed results.

Natura Cosmeticos SA, a company that makes beauty products based on tropical plants, relies on rainforest communities to help it develop new extracts and pays them for their help.

"Working with locals saves us light years of research," said Eliane Anjos, the company's environmental affairs director. "But paying locals isn't easy. It can destroy local cultures and cause social and economic imbalances."

In one community of river dwellers in the Amazon that provides Natura with plant materials, the company wanted to install a simple sewage system to fight childhood illnesses.

Instead, it found itself quashing a demand for a pickup truck by explaining to residents that there were few roads to drive on in the rain-soaked region. TV satellite dishes were also a popular request.

In that same village, one resident took nearly all of the money Natura had put into a community trust fund, abandoned his wife and moved to the modern state capital with another woman.

Experts also disagree on how to define who should receive benefits, how much they should receive and for how long.

OBSCURE MARKET

Brazil has signed international agreements to protect biodiversity and has turned parts of those agreements into domestic law, but like other countries rich in biological wonders, such as many in Africa, it has yet to decide how to deal with biopiracy. Poor governments are often too weak to monitor and enforce biodiversity laws.

As local laws lag, patents that raise biopiracy issues are starting to be dealt with by the World Trade Organization and the UN World Intellectual Property Organization.