The presidential campaign of George W. Bush, frustrated by continued rumors about drug use, took the unusual step yesterday of providing evidence to contradict an accusation made in a book that goes on sale today.

The book, "Fortunate Son," alleges that Bush was arrested for cocaine use in 1972 in Houston and that a judge expunged the record as a favor to political allies of Bush's father, President Bush. The allegation by the author, J.H. Hatfield, is based on anonymous sources, with no information about arresting officer, judge, or any other corroboration.

Bush, asked about the allegation at an Arizona news conference on Monday, said it was "totally ridiculous," and his spokesman said the Texas governor has never been arrested for any drug charge at any location. Many major news organizations chose not to write about the allegation because it is unsubstantiated.