Mike Starr, the original bassist with 1990s US grunge-tinged rock band Alice in Chains, was found dead in Utah.
Police say the 44-year-old's body was found in a Salt Lake City residence, a police spokesman said, while the TMZ celebrity website quoted his father as saying: "It's a terrible shock and tragedy."
An autopsy including toxicology tests will be carried out, said Salt Lake City police spokesman Shawn Josephson, who could not elaborate on the circumstances of the death.
The musician was arrested last month for possession of a controlled substance, TMZ reported, adding that police found painkillers and another drug in his possession at that time.
Alice in Chains emerged in Seattle in the 1990s around the same time as bands including Nirvana and Pearljam, although they were inactive for long periods.
Starr left the band in the 1990s, and lead singer Layne Staley, who suffered from drug addiction, died in 2002.
Tributes were posted on Starr's website, www.wix.com/mikestarr/mike--starr, after his death was reported. "Your music guided me through a very important time in my life. God Speed and RIP!!" said Tanker 43.