(Cover) - EN Showbiz - Janet, Randy and Rebbie Jackson are intent on proving that Michael Jackson's "will is invalid."

The trio are going after the executors of their late brother's estate. They believe Michael's bequest is being managed against his final wishes.

The siblings claims that there is "irrefutable evidence" that the signature on the will in questions is bogus, as Michael was in New York on the date that the document was signed in California.

Despite public furore, Janet, Randy and Rebbie will continue to fight to see that their voices are heard in this matter.

"[They] stand to gain nothing financially by a finding that the will is invalid," the threesome's lawyer released in a press release to ET Online.

Apparently they are most concerned about Michael's three children Prince, Paris and Blanket.

Janet, Randy and Rebbie are aiming to ensure that the King of Pop's wealth goes to his kids, as he desired.

"[They want to replace the executors of the estate and settle matters] in a manner that is in the best interests of the children," the statement read.

Elderly matriarch Katherine lost custody of Paris, Prince and Blanket recently after they were unable to reach her for over nine days.

On Thursday Katherine's guardianship was reinstated, but she will share custody with TJ Jackson.

Janet, Randy and Rebbie have reportedly now been banned from entering the Calabasas home where the kids live with Katherine for vocalising their sentiments on Michael's will. (C) Cover Media