At present the 'Rehab' singer's cause of death is unknown but it is possible her decision to try and quit booze completely after years of heavy drinking
Choosing to quit completely could have caused her body a shock or seizure which killed her at her home in Camden, north London, last Saturday.
A source said: "Abstinence gave her body such a fright they thought it was eventually the cause of her death."
Reports had suggested the 27-year-old star had been drinking heavily and had possibly taken drugs in the days leading up to her death, but her father Mitch has refuted the claims, insisting the opposite is true.
The source added to The Sun newspaper: "He has wanted everyone to know that he, her boyfriend Reg Traviss and her manager believed it was actually the complete opposite.
"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.
"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."
A post-mortem was held on Monday, the day before Amy's funeral, to try and determine the cause of her death but the results were deemed inconclusive and medical officials are awaiting the results of histology and toxicology tests.
Police have now begun probing into what Amy was between 8pm on Friday night and 4pm the next day when she was discovered deceased by one of her security guards.
A source told the Daily Mirror newspaper: "She had a chaotic lifestyle and often she would head out late at night or even in the early hours of the morning to see friends.
"No one really knows what she did after she was checked on by her doctor at 8pm and before she was found dead at 4pm the next day.
"There is a possibility she left her home at some point during the evening, and some of her friends believe she may have headed out later."
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