President Bush’s former sister-in-law denied yesterday that she had given author Kitty Kelley any information about allegations of past drug use by Bush.

Sharon Bush is quoted in Kelley’s forthcoming book about the Bush family as making one of the allegations, and Kelley’s editor said in an interview Tuesday that she had provided “confirmation” for the information.

But Sharon Bush, who is divorced from the president’s brother Neil, said in a statement: “I categorically deny that I ever told Kitty Kelley that George W. Bush used cocaine at Camp David or that I ever saw him use cocaine at Camp David. When Kitty Kelley raised drug use at Camp David, I responded by saying something along the lines of, ‘Who would say such a thing?’

“Although there have been tensions between me and various members of the Bush family, I cannot allow this falsehood to go unchallenged.”

Doubleday, Kelley’s publisher, was quick to dispute her account.

“Doubleday stands fully behind the accuracy of Ms. Kelley’s reporting and believes that everything she attributes to Sharon Bush in her book is an accurate account of their discussions,” said Associate Publisher Suzanne Herz. “Ms. Kelley met with Sharon Bush over the course of a four-hour lunch on April 1, 2003, at the Chelsea Bistro in Manhattan.”

The next day, Herz said, Kelley had a 90-minute phone conversation with Bush in the presence of Peter Gethers, her Doubleday editor. Gethers confirmed the accuracy of the statement yesterday.