Two-thirds of the members serving on an expert medical panel investigating a U.S.-funded AIDS study are receiving grant money from the federal agency at the center of the probe, according to documents and interviews.

The Institute of Medicine (search) said it was aware of the financial ties with six of the nine members of its expert panel but approved their participation because they have special expertise, receive only a minority of their overall funding from the National Institutes of Health (search) and won their grants competitively.

The six panel members are receiving funds from NIH ranging from $120,000 to nearly $2 million a year, according to agency records and interviews by The Associated Press.

IOM, the nation's health adviser, believes the panel's ultimate conclusions about NIH's controversial AIDS study in Africa won't affect the members' NIH funding, and thus there is no conflict of interest, spokeswoman Christine Stencel said.

"When you get into some of these fields or areas, you are not talking about a really huge pool of experts who can be candidates or experts," Stencel said.

"In this case a lot of the great candidates potentially would have had funding from NIH. ... Do you keep off of your committee every great expert out there because they can't have a single penny from NIH or do you strive for a balance, keeping any possible connection like that to an absolute best possible minimum?" she said.

Stencel said IOM rejected two other potential members because they received a majority of their funding from NIH or drug companies tied to AIDS research.

The chairman of the Senate Finance Committee said he is concerned the researchers' financial ties to NIH create a conflict of interest that sullies any conclusions they make.

"If there's financial interest, there's a conflict, and that's a factor to consider when sizing up objectivity," Sen. Charles Grassley, R-Iowa, said.

Frequently the government has appointed experts to scientific panels even though they had connections to the issues, companies or agencies they were investigating. For instance, federal drug regulators recently acknowledged that some advisory panel members who recommended pain killers stay on the market had ties to the makers of the drug.

Legal and medical ethicists said IOM likely didn't violate any laws but should have done more to alert the public to the financial conflicts in the NIH case, especially because the panel members have an ongoing financial relationship with the agency.

"Essentially, what the public will want to know about this report is is this a whitewash or is it actually independent," said Kathleen Clark, a government ethics expert at Washington University in St. Louis.

"It is interesting that they (IOM) revealed this only in response to an inquiry from Senator Grassley and from the media. That's problematic," she said.

IOM's review of NIH's study in Uganda of the AIDS drug nevirapine (search) has international implications.

The study was relied on by the Bush administration to back its decision in 2002 to send hundreds of millions of dollars worth of nevirapine to Africa to help stop the spread of AIDS from mothers to babies. AP reported in December the study violated federal patient protection rules and suffered widespread problems with paperwork and compliance.

NIH officials acknowledge the problems but say they remain confident in the study's overall conclusion, that nevirapine can be taken safely in single doses. NIH asked IOM last fall to independently investigate its conduct in that study.

South Africa is deciding whether to end nevirapine's use for pregnant mothers.

At least four IOM panel members get their money directly from NIH's infectious disease institute, whose conduct is at the center of the IOM investigation. Two others get their funding from NIH's Fogarty International Center, which helps fund research worldwide on issues from AIDS to mental health.

Dr. Mark Kline, an IOM panel member and pediatric AIDS expert at Baylor University, said he receives between $250,000 and $300,000 a year from NIH. He said he went into the study "as objectively as possible and in an open-minded manner and tried to judge on the basis of the evidence."

Kline said NIH money accounts for 5 percent or less of his overall program. "It had never crossed my mind that there would be implications for my funding," he said.

Other IOM panel members with NIH funding:

—Dr. Wafaa El-Sadr, an AIDS expert at Columbia University, received just over $2 million from NIH's infectious disease division last year, NIH said.

—Stephen W. Lagakos, director of Harvard University's Center for Biostatistics in AIDS Research, which received $242,700 from NIH in the past year, NIH said.

—J. Richard Landis, a University of Pennsylvania biostatistics expert who received $136,229 in funding from NIH's infectious disease division last year, NIH said.

—Dr. Charles van der Horst of the University of North Carolina-Chapel Hill, who helped oversee a multimillion-dollar NIH study on the side effects of AIDS medicines. Last year, his project got more than $120,000 in NIH funding, the agency said.

—George W. Rutherford of the School of Medicine at the University of California, San Francisco, who receives funding through NIH's Fogarty Center. NIH and IOM confirmed Rutherford was awarded a five-year grant in 2001 for AIDS training and research. Rutherford said he received $243,308 in the past year.