The contacts by staff with industry officials and others took place before the Foundation for the N.I.H., which has the authority to seek donations for government studies, was given permission to raise private funding for the trial.

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Investigators also found that officials at the alcohol institute “hid facts” from other staff and from the foundation.

Dr. Michael Siegel, a professor of community health sciences at Boston University and an early critic of the alcohol study, applauded the N.I.H. for discontinuing the research.

“This ensures that N.I.H.’s research agenda will be determined by scientific merit, not corporate marketing priorities,” he said. “The N.I.H. research portfolio should not be up to the highest corporate bidder.”

In a statement, Dr. Mukamal denied any wrongdoing and said he and his colleagues “stand fully and forcefully behind the scientific integrity” of the trial.

“We are deeply disappointed that issues raised have led to a recommendation to end the trial and negate the extraordinary efforts of its participants, investigators, scientific and ethics review boards, and many dedicated staff members,” he wrote.

Officials at the alcohol institute lobbied beer and liquor companies to help fund the $100-million trial, The Times reported in March. Scientists were flown to industry meetings where they described the proposed trial and suggested that the results would support moderate drinking.