Cheyenne Brando, daughter of actor Marlon Brando and a possible witness against her half-brother in his upcoming murder trial, lay comatose in a Tahitian hosptial after overdosing on drugs, it was reported Friday.

Physicians at Mamao Hospital told Marlon Brando on Thursday that "the next eight hours are critical" to her health, the Los Angeles Times said, quoting an unnamed source close to the Brando family.A doctor at the hospital confirmed that Cheyenne was a patient there but would not divulge further details.

Cheyenne Brando, 20, is a critical witness in the murder trial of her half-brother Christian, but shortly after he was arrested for allegedly shooting to death her lover, Dag Drollet, 26, she fled to Tahiti.