LONDON – from www.bostonherald.com – The heartbroken sister of pop superstar Michael Jackson told British tabloids her brother was murdered for his billion-dollar fortune.

“We don’t think just one person was involved in the murder,” LaToya Jackson, 53, told the News of the World. “It was a conspiracy to get Michael’s money.”

And she vowed to bring his killers to justice.

“I know who did it and I won’t rest until I nail them,” Jacko’s grieving sister told the paper.

Michael Jackson died June 25 at the age of 50. The cause of his death remains under investigation.

LaToya Jackson, in separate interviews with News of the World and The Mail, did not name the King of Pop’s killers or offer any proof of foul play.

She was clear about the motive.

“I feel it was all about money,” she told the News of the World. “Michael was worth well over a billion in music publishing assets and somebody killed him for that. He was worth more dead than alive.”

And Michael’s older sister dropped this bombshell: He was robbed of $2 million in cash and jewelry as he lay dying in his rented mansion.

LaToya claimed Jacko’s killers used powerful prescription drugs to keep him submissive and away from his caring family.

Jackson’s killers kept him doped up so he’d agree to the grueling 50-show comeback concert series in London that was scheduled to begin today, LaToya Jackson alleged.

Her brother Michael was forced to perform the shows he was rehearsing for when he died, she told News of the World.

LaToya Jackson claimed she predicted her star-crossed brother would never play the long-awaited concerts.

“Less than a month ago, I said I thought Michael was going to die before the London shows because he was surrounded by people who didn’t have his best interests at heart,” she told The Mail.