The tragic death of Glee actress Naya Rivera last week has been confirmed as an accidental drowning by Ventura County Medical Examiner's Office.

The 33-year-old took her four-year-old son on a boat trip on California's Lake Piru a week ago and disappeared after going for a swim without a life jacket.

On Monday her body was recovered from the lake and now a full autopsy has been performed by the medical examiner.

"The circumstances and visual characteristics all indicated that the body was that of Naya Rivera and the identity has been confirmed by dental comparison," the official report read. "The body has been x-rayed and a full autopsy has been performed.

"The autopsy findings are consistent with a drowning and the condition of the body is consistent with the time that she was submerged. No traumatic injuries or disease processes were identified at autopsy.

"There is no indication from the investigation or examination that drugs or alcohol played a part in the decedent's death, but specimens will be submitted for toxicology testing."

The current in Lake Piru is thought to have been "very strong" on the day that Rivera suffered the fatal accident.