Naya Rivera's cause of death has been confirmed as drowning.

The 'Glee' star was found in Lake Piru, California after days of searching after she went missing during a boating trip with her four-year-old son Josey.

The Ventura County Medical Examiner's Office said in a statement: '' 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 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.''

The Medical Examiner's Office insists there was no indication that drugs or alcohol ''played a role'' in her death.

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

It comes after Ventura County Sheriff, Bill Ayub revealed he believed Naya used her energy to save her son before her death.

He said in a press conference: ''It would be speculation to say at this point. There are a lot of currents on the lake that appear particularly in the afternoon. We believe it was mid-afternoon when she disappeared, the idea perhaps being that the boat started drifting, it was unanchored, and that she mustered enough energy to get her son back onto the boat, but not enough to save herself.''

At the time, Ayub says the Sheriff Office is ''confident'' the body found is that of Naya's, although formal identification has yet to take place.

He told the media: ''Based on the location where the body was found, physical characteristics of the body, clothing found of the body and the physical condition of the body, as well as the absence of any other persons reported in the area, we are confident the body we found is that of Naya Rivera.''