Walter Becker, guitarist, bassist and co-founder of Rock and Roll Hall of Famers Steely Dan died earlier this month at 67. Now, a new Rolling Stone feature about the eccentric musician’s life suggests Becker might have died of complications related to hepatitis C virus (HCV), which he likely acquired as a result of years of heroin use in the 1970s and ’80s.

At the time of his passing, friends and family said Becker had been battling health issues for well over a decade. No definitive cause of death has been announced yet, but sources close to the musician say he had been fighting hepatitis C for years and might have died of liver cancer.

The virus was a likely result of Becker’s reported heroin use in the 1970s and ’80s. In January 1980, Becker’s girlfriend Karen Stanley overdosed in the couple’s New York apartment, causing the musician to lose touch with the rest of Steely Dan. To refocus his life, Becker moved to Hawaii, married, bought an apple and avocado farm and focused on healthier habits like tai chi, mountain biking and healthy eating. 

After his long recuperation, Becker picked up music again, touring once more with Steely Dan in the early ’90s and later releasing a Grammy Award–winning album with band mate Donald Fagen. However, the comeback was short-lived. In 1997, Becker’s marriage ended in divorce, and the musician moved back to New York. Band mates said he started drinking again while they were on tour. 

Around the time that Steely Dan’s 2008 album, Circus Money, came out, Becker reportedly started developing liver issues. The musician apparently underwent multiple rounds of hepatitis C treatment and in 2016 took time off for an undisclosed medical procedure before one of the band’s New Orleans shows.

This year, Steely Dan had to start playing shows without Becker. A week before his death, Fagen says he visited Becker in the hospital to cheer him up and told band mate Pete Fogel that he sensed it was the last time he’d see Becker alive. 

For now, Steely Dan says it will continue on, returning to tour this October. The musicians say Becker’s musical legacy of subverting pop music, writing unconventional lyrics and helping to create one of mainstream rock’s most eccentric bands will live on in the music.