The claim was made by British tabloid The Sun after Winehouse was admitted to a London hospital on July 28 after falling ill at her home.
The Rehab singer's representative had at the time released a statement, saying that it was due to an adverse reaction to the medication that she was taking to help kick her drug addiction, and her father Mitch supported it.
But it has now emerged that Winehouse had in fact become sick after allegedly smoking pot for more than a day, and her pals fear that the reported addictions will leave her needing medical help for years to come.
"Mitch does everything he can to protect his daughter - but his 'explanation' for Amy's hospital dash in July was simply untrue," Contactmusic quoted a source as telling the publication.
"She had smoked an inhuman amount of hash which resulted in acute cannabis poisoning. You have to take a s**tload of pot to suffer that severe a reaction.
"It's thought she had been smoking it for 36 hours... She is in need of years of psychiatry and medical treatment if she has a hope (of fully recovering)," the source added.