The Rehab hitmaker died from alcohol poisoning in July, 2011 at the age of 27 after battling drink and drug demons for years.
Critics and fans had feared for her wellbeing after reports of increasingly erratic behaviour, and Status Quo star Rossi is convinced the singer could have been saved with the right advice.
He tells British magazine Event, "What do you think killed Amy Winehouse? Her Pr. She believed it. 'You're so innovative and original!' No, she was pretty good but not as good as they all said she was. She sounded like a load of Sixties singers to me.
"She makes a record about rehab saying 'Oh I don't need that!' and everyone says she's right. Wrong. They said, 'Let her drink more!' They should have smacked her bum and told her 'No!' So many people believe their Pr and it's not true."