Amy Winehouse’s tour manager has quit amid claims the troubled star was ruining his health. Thom Stone is alleged to have found traces of heroin in his system, after passively inhaling fumes claimed to be from the singer and her husband Blake Fielder-Civil’s drug use. Last month Stone presented Winehouse with a doctor’s note outlining that the pressures of managing the singer was harming his health.

A source tells British newspaper The Sun, “He was constantly bailing her out. He was watching them get off their head on drugs and wondering whether Amy was even going to get up on stage. It was a nightmare job.”

A friend of the couple says, “When he produced this note Blake and Amy thought it was a joke. They didn’t get on with Thom and were taking the p**s when he tried to pull that excuse to leave. They wanted rid of him anyway.”

Winehouse disappointed scores of fans at the opening night of her U.K. tour in Birmingham, England, on Wednesday – many of whom walked out of the ‘shambolic’ show or demanded a refund for the poor performance.