The report also alleged that three Napa Valley patients overdosed on amphetamines or cocaine last fall, while three others obtained and used heroin. Furthermore, the report says that a hospital physician testified under oath last year that staff "brings drugs into the facility in exchange for cash."

The report, posted on the Justice Department's website late Tuesday, also said that the state Department of Mental Health had denied federal investigators access to the Northern California facility and to two other state hospitals it wants to investigate: Atascadero on the Central Coast and Patton in San Bernardino County.

"As we repeatedly advised state officials, however, our investigations proceed regardless of whether officials choose to cooperate," wrote Bradley J. Schlozman, an acting assistant attorney general, in the Napa Valley report.