They said three patients receiving Diprivan to treat severe seizures had suffered cardiac arrest, and two died. The doctors said the clinic stopped using Diprivan to treat such patients because of the danger.

The drug's manufacturer, AstraZeneca PLC, warns that patients using Diprivan should be continuously monitored, and in a tiny number of cases patients using it have suffered cardiac arrest, although it was not clear the drug was to blame.

Authorities are investigating allegations that the 50-year-old Jackson had been consuming painkillers, sedatives and antidepressants. Any criminal charges would depend on whether Jackson had been overly prescribed medications, given drugs inappropriate for his needs, or if doctors knowingly prescribed Jackson medications under an assumed name.

Edward Chernoff, an attorney for Jackson's doctor, Dr. Conrad Murray, said Friday through a spokeswoman that he had agreed with investigators not to comment until information is released through official channels. Murray was in Jackson's rented mansion when the singer went into cardiac arrest in his bedroom on June 25.

Murray has spoken to police and authorities say he is not a suspect. In an earlier interview, Chernoff said Murray never gave or prescribed Jackson the painkillers Demerol or OxyContin, and denied reports suggesting that the doctor gave the pop star drugs that contributed to his death.

Chernoff would not discuss what drugs the doctor administered to Jackson, but said they would have been prescribed in response to a specific complaint.