"We are profoundly saddened to report that our friend died in his sleep ... Jay was a beautiful human being who will be missed," read the posting Sunday on Undertow Music Collective's Web site.
Bennett died at his Urbana home early Sunday and an autopsy was being performed, friend and fellow musician Edward Burch told the Chicago Sun-Times in a story posted online late Sunday.
"The family is in mourning and is unavailable for comment at this time," Burch said.
A cause of death was not immediately available. A message left for the Champaign County Coroner on Sunday was not immediately returned.
After earning degrees in secondary education, math and political science at the University of Illinois at Urbana-Champaign, Bennett worked as a sound engineer and played instruments for Wilco from 1994 to 2001.
His contributions were key to the success of the band's first album, "A.M.," as well as "Being There," "Summerteeth" and "Yankee Hotel Foxtrot." Most recently, Bennett had been wrapping up work on his fifth solo album, "Kicking at the Perfumed Air," and performing with the alternative rock band he co-founded, Titanic Love Affair.
In April, after sustaining injuries to his hip from a fall off the stage while playing with Titanic Love Affair, he wrote on his MySpace page that he needed a hip replacement but had no health insurance. He also wrote about how the experience with the hip pain had changed his outlook on life to an extent.
"This whole experience has really taught me to look both inward and outward for support, and I've learned things about myself that I thought I had completely figured out years ago," he wrote. "Family and friends have helped me to keep faith in a future that will actually be much more carefree than my constricted present state. I encourage you all to tell me stories of recovery, as they really do help... All in all, I'm 'in a really good place' right now; I'm just waiting until I can make it all happen."
Earlier this month, Bennett sued Wilco lead singer Jeff Tweedy, claiming he was owed royalties for songs during his seven years and five albums with the group.
In the breach-of-contract lawsuit filed in Cook County Circuit Court, Bennett also claimed that he deserved money from the band's 2002 documentary, "I Am Trying to Break Your Heart." The film documents the making of "Yankee Hotel Foxtrot."
"We are all deeply saddened by this tragedy," said Jeff Tweedy in a statement
released by Wilco's publicist. "We will miss Jay as we remember him - as a truly
unique and gifted human being and one who made welcome and significant
contributions to the band's songs and evolution. Our thoughts go out to his
family and friends in this very difficult time."