Jermaine Jackson has taken aim at Wade Robson over allegations his late brother Michael molested the choreographer when he was a child, branding the dancer's claims "a big lie".

Robson has asked a California judge to allow him to make a late creditor's claim against Jackson's estate after alleging he was abused by the singer between the ages of seven and 14 at the superstar's California and Las Vegas homes.

Jackson's estate attorney Howard Weitzman blasted the claims, and now the Thriller hitmaker's brother Jermaine has launched an angry tirade at Robson, who took to the stand at the singer's 2005 child molestation trial to deny he had ever been abused by the pop star.

Jermaine tells, "Wade Robson is full of s**t. Wade Robson and his mother helped me with my book. He got on the stand and told the courts that Michael never touched him and it's the truth. I really don't know what's going on, there's no truth to it. It's a big lie. Michael can't defend himself, Michael's not here."