Michael Jackson's family raided his home to confront him over his drug use.
The late pop icon tried desperately to conceal his abuse of prescription medications from his siblings and even ordered his bodyguards not to let them in his house.
His brother Tito Jackson said: "I never saw him on drugs. Not once. He deliberately did it away from us. He didn't want his family to know anything about that part of him. He did almost everything in his power to make sure we didn't know.
"We had to act. It was me, my sisters Janet, Rebbie and La Toya and my brothers, Jackie and Randy. We bust right into the house and he was surprised to see us to say the least.
"We went into one of his private rooms and had a discussion with him. Some of us were crying. We kept asking him if it was true what we had heard that he was using drugs. He kept denying it. He said we were over-reacting. We also spoke to a doctor and he assured us it was not the situation. He said he was there to make sure Michael was healthy.
"We didn't know what to believe. We talked about it again and again for hours but we just couldn't get through to Michael."
The family tried repeatedly to speak to Michael - who died of a suspected cardiac arrest last month aged 50 - about his addiction but the reclusive star went to increasing lengths to keep them away.
Tito added in an interview with Britain's Daily Mirror newspaper: After that occasion we tried many times but his team of people just shut us out, they would not let us close. They literally shut us out.
"I don't know if they were just doing their job or if it they were part of some kind of conspiracy. I do know that Michael would say to them, 'I don't care who it is, don't let anybody on my property if they haven't called first.'
"In the first few intervention attempts his staff and security would not let us on the property. They would block the road into Neverland with other vehicles so we couldn't drive in. I went up there twice trying to get through before we finally did."
Tito - who first became aware the singer had a drug problem when he was treated in a London rehab clinic in 1993 - tried his best to help the star, begging his friends to keep an eye on his brother.
He said: "I would always tell my musician friends who played in his band to watch out for my little brother, make sure he's OK."
Meanwhile, Tito - along with several of his siblings - believes Michael's body should be laid to rest in his former Neverland home, with the Californian ranch turned into a tourist attraction.
He said: "Michael said he never wanted to live at Neverland again. He said he would go and visit, enjoy the amusements and party, but he would never stay there as a residence.
"But I think that's the place he would want to go now because it's his legacy. I think he would want to share the whole thing. When you're at Neverland you can just feel his whole spirit there."
Michael quit Neverland in 2005 after he was acquitted of child abuse charges.