Amy's strained relationship with her father has been laid bare for the first time in an explosive new book, reported Sun online.
The revelation comes just a week after it was reported that Amy's estate was worth less than 180,000 pounds after her family used her estimated 10 million pounds wealth to pay off their debts.
Now, the book claims that the tormented star, who battled drink and drug addiction before her death in 2011, was so devastated over her parents' divorce that she later smoked dope, self-harmed and took an overdose of pills.
It has always been thought that Amy's drug problem began when she met her future husband, Blake Fielder-Civil, and got hooked on heroin.
But one friend said, "Amy went through a lot of pain at her parents' separation. She might have put on a front like she didn't care but to her, seeing her father leave her for another woman was the ultimate abandonment.
"By ten she'd had her first spliff and, in some people's eyes, was already on a road to ruin.