(CNN) -- No signs of foul play or significant trauma were found during the autopsy of Paul Gray, the bassist for the Grammy-winning metal band Slipknot, the medical examiner said Tuesday.
The cause of Gray's death will not be determined until toxicology results are available, which could be four to six weeks away, said Dr. Gregory Schmunk.
Gray, 38, was found dead Monday morning by staff at a TownePlace Suites near Des Moines, Iowa, said Sgt. Dave Disney of the Urbandale Police Department.
The autopsy did show that Gray had been dead for several hours before his body was found, Schmunk said.
Slipknot -- whose fans are affectionately known as "maggots" -- was formed in Des Moines in late 1995 and became immediately recognizable for the dark and often grotesque homemade Halloween masks its nine members wore on stage. The band won a Grammy award in 2006 for best metal performance for "Before I Forget."
Slipknot's self-titled debut album went platinum in 2000. Its fourth album, "All Hope is Gone," spent 69 weeks on Billboard's Top 200 charts, debuting at No. 1 its first week in 2008.
Gray was arrested in Iowa in 2003 on drug possession charges when police found small amounts of marijuana, two syringes and a substance that field-tested positive for cocaine after he was involved in a wreck with another motorist.
CNN's Denise Quan contributed to this report.