Brandon Blackstock's official cause of death has come to light, days after the talent agent and ex-husband of Kelly Clarkson died of natural causes at age 48.

Brandon Blackstock, ex-husband of music star Kelly Clarkson, died last Thursday, August 7. An official cause of death for the 48-year-old has been confirmed. Silver Bow County Coroner Dan Hollis told PEOPLE Monday that Blackstock died of melanoma,

The talent manager “passed away peacefully at his home in Butte, Mont., on Aug. 7 under hospice care surrounded by his family.”