The death of Julia Roberts' half-sister, Nancy Motes, is being investigated as a suicide, the Los Angeles coroner's office said. Motes' family issued a statement saying the troubled production assistant was found dead of an apparent drug overdose Sunday. She was 37. "Nancy Motes was found dead at a residence in the bathroom yesterday, pronounced dead by the LA Fire Department at 2:12 PM yesterday. Not sure whose residence it was. She was found in a bathtub that had water in it. We're taking it as a suicide, not a drowning," the coroner's office said in a statement to UsMagazine.com Monday. "She's being examined today. We are waiting for the doctor to provide his findings," the statement to Us continued. "There were prescription and non-prescription drugs found at the scene. Cannot tell you what those drugs were. The role the drugs may or may not have played is not yet known. The investigator at the scene listed at this point that he is going with suicide and we are waiting for the doctor to finish the examination. We haven't gotten anything yet." Motes was the daughter of Roberts' mother Betty Lou and Roberts' step-father, Michael Motes. Roberts is a current Oscar nominee for her performance in "August: Osage County."