SAN FRANCISCO (AP) _ David Kingsbury, an assistant director of the National Science Foundation and a White House adviser on biotechnology, is being investigated for possible conflict of interest, a newspaper reported Friday.

Kingsbury is ''suspected of having conflicts of interest by serving on the boards of biotechnology companies while helping shape regulations governing the industry,'' the San Francisco Chronicle reported in Friday editions.

Kingsbury, a former University of California researcher who joined the Reagan administration in 1984, denied the charges and said they were being spread by government officials trying to discredit him.

The Justice Department and the Office of Government Ethics are reviewing the allegations.

''The National Science Foundation did ask us to make a preliminary investigation to see if there is a conflict of interest,'' said John Russell of the Justice Department. ''That is being done.''

The matter is being handled by the agency's criminal division, Russell said.

Kingsbury is chairman of the influential Biotechnology Sciences Coordinating Committee, part of the White House Office of Science and Technology Policy.

The controversy involves Kingsbury's annual financial statements and hinges mainly on whether he fully divulged all his ties to Porton International, a London-based biotechnology company, and its American subsidiaries.

Inquiries into Kingsbury's business affairs started in April after a Porton International representative visited the Environmental Protection Agency in Washington and presented a promotional brochure that named Kingsbury as a director of one of the subsidiaries, IGB Products of San Leandro.

EPA officials turned the matter over to their attorneys, who then notified the science foundation.

''Whether or not he is in conflict is not our call to make, but somebody needs to pass judgment on it,'' said John Moore, an EPA assistant administrator.

Kingsbury's latest financial disclosure statement also shows that earlier this year he bought stock in the Chiron Corporation of Emeryville, one of the nation's leading biotechnology companies.

He told the Chronicle he has since sold the stock on the advice of science foundation attorneys.

''I admit that (the purchase) was probably unwise,'' he said. ''It never occurred to us that that was a conflict.''