Katherine Jackson Kept Under Wraps, Away from Grandkids

Katherine Jackson has been stashed away from her grandchildren since returning to Los Angeles ... out of fear they'll reprogram grandma and derail her legal battle with Trent Jackson.

Sources connected to the family tell us Michael's children -- Paris, Prince and Blanket -- didn't even know Katherine was coming back and as of Friday, had not seen her. Remember, she flew back from London Wednesday night, and her daughter Rebbie desperately tried to block our camera at LAX.

Other family sources say rather than taking the matriarch to her own home, she was secretly taken to one of her children's homes -- and it has everything to do with the elder abuse lawsuit.

Remember, the main reason Katherine even came back is to testify against her nephew, Trent. He's made it clear he believes Rebbie and Jermaine Jackson are masterminding the whole case in an effort to gain control of Katherine's money.

We're told Trent's camp thinks Katherine's kids are worried Paris and Prince will encourage grandma to drop the lawsuit. You'll recall ... Paris went off on Jermaine and other siblings in 2012 when Katherine was taken to Arizona for nearly 2 weeks. She equated it to a kidnapping.

Our sources point out the fact Katherine still hasn't seen her beloved grandchildren -- after being gone for 2 months -- is a strong sign someone doesn't want a repeat of 2012.