Credit: Guy Viau

The autopsy for That '70s Show star Lisa Robin Kelly has been completed after her sudden death last week. Lisa was found dead on Friday, August 16; she was 43 years old.

Unfortunately, there’s no clear answer yet on the actress’ cause of death as the Deputy Medical Examiner has “deferred” a final result pending “additional tests and tissue studies,” reports E! News.

"We are probably looking at approximately six to eight weeks before the case will be closed,” says the Los Angeles Coroner’s office. “In the interim, we are unable to comment further until all of the results have been received and the case officially closed by the Coroner."

Upon her death, Lisa, who played the older sister of Topher Grace’s character Eric Forman, had voluntarily checked herself into a treatment facility to battle “the addiction problems that have plagued her these past few years,” her agent told E! News.

Lisa’s boyfriend took her to a hospital on Sunday, August 11, where she registered a startling high blood alcohol level of .34 (for comparison, the legal driving limit in California is .08). She was admitted to Pax Rehab House in Altadena, California, where she was found dead on Friday.

Source: E! News