Michael Lohan has revealed that he fears prescription drugs are killing his daughter.

In an interview with RadarOnline.com, Lindsay Lohan’s semi-estranged father blames her downward spiral – professionally and personally – is due to the drugs she’s on.

"I'm going to get her off the prescription drugs that she's on," he said. "I hate it when people talk about illegal drug abuse... because it's not just drinking and illegal drugs that kill you. Prescription drugs can destroy and kill a person and are sometimes harder to stop. Look at Heath Ledger and Michael Jackson."

Lindsay, a notorious partier who has a DUI, has regularly attended AA meetings, has been caught with cocaine and has had three stints in rehab, shocked onlookers at the debut of her Spring 2010 collection for Ungaro in Paris on Sunday. The Irish-American actress/singer looked frail, disheveled and out of it as she walked down the runway hand in hand with a model.

Though Michael Lohan won’t identify the specific medications he believes Lindsay is abusing, he is confident that they are making his daughter a ghost of what she once was.

"You know why Lindsay's not acting in feature films right now? Because she can't," he said. "Because the girl with all the talent is hidden and buried deep inside this fungus that's grown because of the prescription drugs. She can't be herself. When you hug her she's like, vacant inside. When she kisses or holds me I get chills, and not in a good way – in a bad way."

Lohan says he noticed this when he spent time with his 23-year-old daughter after her the break-in at her Hollywood home.

"She's a different person. I was out there for a week when she was living at the Sunset Marquis Hotel and I would sit there and cry. It was horrible. This was not the kid I raised," he said.

The father of four, who is divorced from Lindsay’s mom Dina and has spent time in jail for stock fraud and a probation violation, says he wants to make his daughter’s troubles public because he fears for her health and safety, and wants the people who are taking advantage of her to stop.

"I don't care what anyone says about Lindsay. The Lindsay Lohan I lived with when I was married was a focused, intelligent, gifted girl that needed no prescription medication, no assistance from a therapist,” he said.

“Whoever the people are that came into her life and convinced her otherwise should be thrown in jail, because they're the same type of people who are responsible for the deaths of Heath Ledger, Michael Jackson and DJ AM.

“Everything was fine in our family until Dina and I got divorced. And that's when all the kids' lives started to unravel... including Lindsay's."