KOMO-TV, citing an unidentified source, said the body was that of Staley, 34.
A King County medical-examiner's investigator said his office removed a body from the Staley address and planned an autopsy today, but he refused to confirm the identity of the person. He said it appeared the person had been dead for some time and would have to be identified scientifically.
Staley had a history of substance abuse, and in the early 1990s publicly acknowledged an addiction to heroin.
Alice in Chains, formed in Seattle in 1987, was part of the early '90s heyday of grunge. The band was mentioned in the same breath as Nirvana and Soundgarden.
The band's debut album, "Facelift," was released in 1990, and the song "We Die Young" became a top-5 metal track.
In 1991, the band was nominated for an American Music Award for Favorite Heavy Metal Artist.
The band's last release was "Nothing Safe — Best Of The Box" in 1999.
Staley also fronted the side band Mad Season.
Fans last night were already mourning Staley's death on bulletin boards on music sites.
One wrote: "You were an amazing man Layne; a tortured soul, but a loved one. Wherever you are, I hope you feel how much you and your music meant to your fans. Rest in peace."