Vesta Williams Autopsy Complete

9/25/2011 11:45 AM PDT

Vesta Williams -- Autopsy Complete

The autopsy of R&B singer Vesta Williams has been completed today -- and sources tell TMZ the cause of death is undetermined pending toxicology results, which will take 4-6 weeks.

Williams was found dead in her hotel room on Thursday. Sources tell TMZ several prescription pill bottles were found at the scene and no foul play is suspected.