Righteous Brothers singer Bobby Hatfield's death was caused by cocaine and not just heart failure, according to the official autopsy report.
Hatfield, 63, died Nov. 5 just hours before a Righteous Brothers concert. An initial autopsy found Hatfield had advanced coronary disease. A heart attack due to the disease was listed on Hatfield's death certificate, according to the Associated Press.
Dr. Richard Tooker, chief medical examiner for Kalamazoo County, Mich., said a final cause of death was not determined until after toxicology reports were completed. The death certificate will be changed to reflect cocaine as the cause of death, he said.
Tooker's office received the report of cocaine intoxication on Dec. 24, but he asked for the information to be released after the holidays out of respect to Hatfield's family.
Hatfield and his partner, Bill Medley, had hits including "Unchained Melody" and "You've Lost That Lovin' Feeling."