La Toya Jackson last night claimed her brother Michael was "murdered" for his millions.
She alleged his death was the result of "foul play" by hangers-on.
La Toya, 53, said: "Michael was murdered. And we don't think just one person was involved. Rather, it was a conspiracy of people.
"Michael was worth well over a billion in music publishing assets and somebody killed him for that. He was worth more dead than alive.
"He was surrounded by a bad circle. Michael was a very meek, quiet, loving person. People took advantage of that."
She added: "A couple of years ago Michael told me he was worried that people were out to get him.
"He said, 'They're going to kill me for my publishing. They want my music catalogues and they're going to kill me for these.'" La Toya claimed Michael, who she last saw three weeks before his death, had wanted to quit music to make films - and only wanted to do 10 shows in London, not the 50 he was booked for.
She claimed she knew who was responsible for his death but could not name them for fear of prejudicing police inquiries. La Toya also claimed millions of dollars of cash and jewels disappeared from Jacko's house the day he died.
She revealed that, contrary to reports that he was found in bed at his rented villa, he was actually found in the bedroom of personal live-in doctor Conrad Murray, who "disappeared" when she later tried to quiz him about what had happened.
La Toya was with her brother's three children when they took a last look at their father as he lay in hospital.
"We hugged and kissed him and the children lifted up his hands," she said. "His eyes were half open and he looked like he was sleeping."
Then, last Monday, she watched as daughter Paris fastened a necklace she had bought round his wrist and garlanded his body with coloured stones at a family viewing at the cemetery. The necklace held a metal heart designed to change colour when it touched his skin.