Crooner Tony Bennett's drug demons are coming back to haunt him in a damning new book penned by his ex-wife SANDRA GRANT. Grant and Bennett divorced 23 years ago and now the singer's bitter ex is revealing all about their troubled marriage in a shocking new tome. In the book, she'll portray the I LEFT MY HEART IN SAN FRANCISCO singer as a jealous drug abuser, who ruined her financially. Bennett has spoken openly about his past drug problems, and felt sure that part of his life was over. A source tells US tabloid the Globe, "Tony will be outraged over Sandra's accusations. He's admitted he used drugs in the '70s and stopped cold. Why raise that 30 years later?" The most shocking claim in the new book is Grant's revelation she saved Bennett's life once when he overdosed on cocaine. She also blasts her ex-husband over his decision to turn the family's finances over to his young son DANNY, who has remained his manager and was namechecked by Bennett at the 2007 Grammy Awards. Grant explains, "The death knoll for our marriage was when he put our financial affairs in the hands of his son, who was barely out of high school."