JOE JACKSON thinks that his son Michael was murdered, and at least one person is convinced that he's right:

La Toya.

And she wants revenge.

"We don't think just one person was involved in the murder," La Toya told London's News of the World. "It was a conspiracy to get Michael's money.

"I know who did it, and I won't rest until I nail them!"

In an exclusive interview with News of the World, La Toya, who claims to be the closest person to Michael, reveals that she and the family are convinced her brother's apparent drug overdose has "foul play" written all over it.

"Michael was worth well over a billion in music-publishing assets, and somebody killed him for that," she says. "He was worth more dead than alive."

Making Michael sound too much like Britney Spears, La Toya says that he was given addictive drugs to keep him submissive; that the people who manipulated him kept him away from his family; that they worked him to exhaustion; and that they stole $2 million in cash and jewels as he lay dying.

As for the coroner's report, La Toya says: "I think everyone will be surprised when the results come out.

"I can't discuss that any further because of the ongoing police investigation. But I can say newspaper reports that there was methadone in his body are inaccurate.

"He had many needle marks on his neck and on his arms, and more about those will emerge in the next few weeks. But nothing has changed my mind that this was murder, and I won't give up until I find out what killed my brother.

"A couple of years ago Michael told me he was worried that people were out to get him. He said, 'They're gonna kill me for my publishing. They want my catalogues and they're gonna kill me for these.'

"I knew something terrible was going to happen."

As for who actually killed Michael, La Toya says she knows . . . but she can't say.

"I don't want to jeopardize the police investigation," she says. "But not everybody had Michael's best interests at heart. A month ago I felt Michael was going to die before he did his London concerts.

"I was at my home, just three minutes from Michael's," she tells News of the World, "and was talking to a friend about the fact that Farrah Fawcett and Ed McMahon . . . had just died.

"I said, 'There's going to be another one because they always go in threes.' About an hour and a half later my father called to say Michael had been rushed to hospital.

"I jumped into my car and kept calling my mother's assistant asking, 'How is he?' But he wouldn't say.

"Finally, I heard mother in the background yelling, 'Why don't you just tell her?'

"Then she grabbed the phone off him and screamed: 'HE'S DEAD!' I nearly crashed my car. My legs went weak."