Jul 28, 2011 13:10 GMT  ·  By

In his eulogy, Amy Winehouse’s father Mitch said that the singer had been off drugs for 3 years and off alcohol for about 3 weeks at the time she was found dead last weekend. He’s also been telling friends that he’s convinced it was quitting drinking that killed her.

According to an unnamed source speaking to The Sun about the singer’s death, Mitch told mourners at her funeral that she wanted to quit drinking cold turkey and it was precisely this that killed her.

Because she’d been addicted to alcohol for so many years, when she quit cold turkey, her body could not handle the withdrawal symptoms and simply shut down.

The same insider claims that Amy’s doctor had warned her that she was to quit drinking because of her frail health, but recommended she did it gradually – something she apparently did not agree with.

“Abstinence gave her body such a fright they thought it was eventually the cause of her death. [Mitch] wanted everyone to know that he, her boyfriend and her manager believed it was actually the complete opposite,” the spy says for The Sun.

“He said doctors had told Amy to gradually reduce her intake of alcohol and to avoid bingeing at all costs. Amy told him she couldn’t do that. It was all or nothing and she gave up completely,” adds the insider.

It would turn out to be her worst decision.

“Mitch said the shock of giving up, after everything she had been through over a bad few years, was just too much for her to take,” the spy explains.

Doctor Carol Cooper was asked by The Sun whether the abstinence theory was feasible and, it turns out, it is.

Quitting cold turkey can lead to DTs (delirium tremens) in heavy drinkers, which can end in coma or, as the family believes was the case with Amy, seizures, Cooper says.

However, this is just speculation. An autopsy performed on the 27-year-old singer was inconclusive, which means the exact cause of death will be determined once toxicology results are in.