Joe Jackson secretly tried to get his son Michael sectioned last year (08) - because he feared the star's alleged addiction to drugs would kill him.
The King Of Pop passed away in June (09) and reports claim prescription drugs were involved in his death.
Joe Jackson reportedly tried to intervene and get the singer into a psychiatric rehabilitation centre - but his wife Katherine blocked the move.
Family friend Geraldine Hughes tells Britain's News Of The World newspaper, "Joe was trying to save his son's life by getting him help. He knew more than anyone else the extent of Michael's drug problems.
"One day he barged in on Michael who was clearly on drugs. Joe phoned me expressing his concerns and that he wanted to take action.
"In the U.S. you can get a court order to make the person in trouble get help. Joe felt he needed the backing of the family - but everyone refused, insisting Michael was okay. I believe this is why he died in the end."