Speaking out for the first time since Michael Jackson's sudden death on June 25, the singer's sister LaToya Jackson, 53, is raising alarming allegations.

"Michael was murdered," LaToya claims in an exclusive interview with London newspaper the News of the World.

“We don't think just one person was involved in the murder," she added, refusing to name the people she believes are responsible for the death during her four-hour interview in L.A. “It was a conspiracy to get Michael's money."

According to LaToya, Jackson himself always feared for his life. "A couple of years ago Michael told me he was worried that people were out to get him,” she told the paper. "He said, 'They're gonna kill me for my publishing. They want my catalogues and they're gonna kill me for these.' "

In the months leading up to his London performances, Jackson told his sister that he was on a six-month detox to prepare for his comeback, but LaToya says she had other suspicions.

"Michael was being inappropriately treated by people who got him hooked on drugs,” she told the News of the World. "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 despite the family’s best efforts to reach out to Jackson recently, LaToya claims that those plotting against Jackson “tried to keep the family away at all times.”

LaToya is not the only family member who believes there was a conspiracy to take Jackson’s life. The family patriarch, Joe Jackson, echoed his daughter’s sentiments, telling ABC News on Friday, “I do believe it was foul play. I do believe that."

But while the tragedy has left the Jackson clan broken-hearted, "this has united the family," LaToya told the News. "We're all in pain and suffering the loss of Michael ... but we're also determined to get to the bottom of what happened to him."