Michael Jackson's children have been quizzed by the Los Angeles Department of Children and Family Services to see if they were ever exposed to prescription drugs.
Michael Jackson's children were quizzed by social workers hours after the star's death.
Less than a day after the 'Thriller' singer passed away from a suspected cardiac arrest, the kids - Prince Michael, 12, Paris, 11, and seven-year-old Prince Michael II, known as 'Blanket' - were subjected to a series of meetings with the Los Angeles Department of Children and Family Services (DCFS) following allegations the 50-year-old star was addicted to painkillers to see if they had been exposed to narcotics, including the heroin substitute methadone.
A source said: "The investigation was initially launched because drugs are so heavily involved. But in this particular case there are red flags from all the family history and from Michael's prior involvement in molestation cases."
The DCFS investigation could also affect any custody disputes between the late star's mother Katherine - who was named legal guardian of the children - and Debbie Rowe, mother to the two eldest children.
The source added to Britain's The Sun newspaper: "The DCFS has 27 days to investigate the case and close it.
"They will check everyone involved in the children's lives for a criminal background.
"If they are satisfied the kids have been raised in a decent environment, then no further action will be taken.
"But if they're not satisfied, that's when they take it to court."
Legal experts believe Katherine will be granted custody, but she is also likely to be assessed.
Attorney and family law expert Michael Dave said: "The DCFS investigate areas such as neglect and abuse.
"They are likely to give Katherine an evaluation, carried out by a neutral expert, to determine how suitable the potential guardian is to take custody of the children full-time." | 
