The White House has canceled a conference that would have forced the country's premier AIDS researcher to confront claims that the virus he has identified as the cause of the lethal disease might not be the cause at all.

Dr. Robert Gallo, the star scientist at the National Institutes of Health, is the man who pinpointed the human immunodeficiency virus (HIV) as the cause of AIDS. Since Gallo's discovery, the NIH, which controls the largest share of the money for AIDS research, has denied funds to scientists with other ideas, even though their theories have been published.

Foremost among the researchers with a fresh point of view is Dr. Peter Duesberg of the University of California at Berkeley. A member of the National Academy of Sciences, Duesberg studied HIV in Gallo's laboratory under a fellowship and concluded that it did not meet the standard criteria for a disease-causing agent.

Duesberg questioned the HIV theory in an article in the medical journal Cancer Research last March. As yet, there has been no official response from Gallo. The editor of Cancer Research, Dr. Peter MacGee, is surprised at the silence from Gallo. "Dr. Duesberg is an excellent scientist. He has a very good reputation. We had expected that there would be more official response to it," MacGee told our reporter Sallie Dinkel.

Instead, Gallo apparently dismissed Duesberg's theory without explanation. Gallo did not return at least a dozen calls for comment.

Among those seeking an answer to Duesberg's challenge was Jim Warner, a senior analyst for domestic policy at the White House. Warner called Dr. Harvey Bialy, the research editor at the medical journal Bio/Technology who had planned a workshop called "How Does HIV Cause AIDS?" to discuss Duesberg's claims, among other topics.

According to Bialy, Warner offered to cohost the workshop under the auspices of the White House because he was frustrated about the inadequate responses he had gotten to Duesberg's theory. The White House label would guarantee the attendance of Gallo and other experts. "Warner is quite skeptical himself about the veracity of the virus-HIV hypothesis," said Bialy. Warner would not respond to our questions.

In spite of initial enthusiasm, the White House conference, scheduled for Jan. 19, was finally taken off the calendar shortly before that. Warner tried to get it rescheduled, but he couldn't, and it was permanently canceled, according to Bialy. Doug McCormick, chief editor of Bio/Technology, said: "The impression was that the pressure came from the NIH." When we asked Warner about the conference, he said, "I can't talk about that."

Gallo plays a big role in directing the flow of money to AIDS research, according to many scientists in the field. "Robert Gallo doesn't support any alternative views," Duesberg said. "As long as this {the HIV theory} goes unchallenged, it will have an inhibiting effect on research."

Hundreds of millions of research dollars are spent each year on the assumption that HIV causes AIDS. Medical experts we questioned believe that federal health authorities would be embarrassed if that assumption were wrong.