Michael Jackson's Alleged Molestation Victim On the Hunt for $20 Mil Boy

The man who triggered a cascade of child molestation allegations against Michael Jackson has disappeared ... at least according to his sister who is scared to death her family is getting dragged into a posthumous child molestation lawsuit against the King of Pop.

Wade Robson, a choreographer/producer is suing MJ, claiming he was molested by Jackson for 7 years at the Neverland Ranch ... starting when he was 7.

Robson wants to take the deposition of the most famous MJ accuser, Jordan Chandler, who scored a $20 million settlement from the singer back in the '90s.

Problem is ... Robson's lawyers can't find Chandler, who's now 36. So they've asked to take the depo of Chandler's sister, Lily. They want to ask her if she knows Jordan's whereabouts, and whether she witnessed any sexual molestation at the Ranch.

Lily's freaked out, and has filed legal docs pleading with the judge to block the depo.

Lily claims her family -- especially Jordan -- has been viciously threatened by MJ fans, and if she resurfaces it will only stoke the coals. She attached some emails directed at her brother, including one that says "F*** you Jordan. U destroyed the king but karma is a bitch. your time will come."

Lily also says she was only 5 when she started going to Neverland and has no memory of any molestation.