The 60-year-old jazz singer received the results along with Amy's mother Janis on Tuesday, and they are "pleased" to clear up rumors the 'Back to Black' musician died from taking drugs, even if the report doesn't help their grief.
He said: "This doesn't make me feel the loss of my daughter any less, but we are pleased to be able to set the record straight to a certain extent."
Mitch also explained Amy's boyfriend Reg Traviss – who had been dating her for two years prior to her passing – didn't recognize the person portrayed as a drug-taking hell-raiser in the wake of her shock death, because Amy had changed her lifestyle so much.
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He added to The Sun newspaper: "Reg has said that the person that she has been painted as in some quarters was just so far away from the Amy he knew. Some of the stories of her last few days were just not how they led their life together."
The results did show the 'Rehab' singer had alcohol in her body, but it is unknown whether that played a part in her death.
A source close to the family said: "The report is the hardest thing Mitch has ever had to read.
"The family had been upset at some of the speculation about the circumstances surrounding her death and at people coming forward claiming to know what happened who clearly did not.
"They wanted to end rumors about drugs. Mitch made it clear at the funeral how he thought it happened - and these results begin to back that up."
Last night, a statement released by her family read: "Toxicology results returned to the Winehouse family by authorities have confirmed that there were no illegal substances in Amy's system at the time of her death. Results indicate that alcohol was present but it cannot be determined as yet if it played a role in her death.
"The family would like to thank the police and coroner for their continuing thorough investigations and for keeping them informed throughout the process. They await the outcome of the inquest in October."