Amy Winehouse "went mad" when her father foiled her attempts to sneak cocaine into rehab.
The late singer - who battled drug and alcohol addiction throughout her life before dying of alcohol poisoning aged 27 in July 2011 - tried to get drugs brought into a private hospital in London via a teddy bear and a bouquet of flowers, and her family had to employ extra security to stop drugs being taken into her room.
Amy's dad Mitch Winehouse fully blames her ex-husband Blake Fielder-Civil - who she had a turbulent two-year marriage with before their divorce - for getting her into Class A drugs, insisting she was "always against" such substances until she met him in a London pub in 2005.
Writing in a new memoir, Amy, My Daughter, he explains: "Amy had an incredible power of recovery, given the quantity of poisonous substances involved. But a few days later, I had a call from the hospital to tell me one of Blake's friends had smuggled drugs into the hospital, crudely stuffed inside a teddy bear.
"On Monday, June 16, Amy had another seizure. She was taken to The London Clinic. We had security guys working shifts to look after her by this time and the next day I took a call from one of them to warn me that a package was on its way.
"I jumped in my cab, and reached the clinic just in time to see a known drug-dealer with a bunch of flowers for Amy. The security man searched the bouquet and found a rock of crack cocaine. Amy went mad when she found out we'd intercepted the drug."
Despite warnings from her parents, the Rehab hitmaker secretly married Blake during a holiday to Miami in May 2007 and when the singer called her father to tell him the good news he was left speechless.
He wrote: "I couldn't say anything to her. I pretended I couldn't hear her properly and hung up. I was beside myself with sadness for Janis.
"It was later that year, on the evening of Monday, August 6, when Amy had her first seizure. She was alone with Blake. He put her in the recovery position but instead of calling an ambulance, he phoned Juliette, one of Amy's oldest friends, who drove her to hospital.
"Now I knew I'd been wrong in thinking Amy was stronger than Blake. It appeared to be the opposite. As the terrible months that followed were to make clear."