He told TMZ: "My brother Harvey is obviously a very sick man. I've urged him to seek immediate professional help because he is in dire need of it.
"His remorse and apologies to the victims of his abuse are hollow. He said he would go away for help and has yet to do so."
Harvey is reportedly blaming Bob for leaking the sexual misconduct story in order to get him removed from their company, but the 62-year-old producer has branded his disgraced sibling a "world class liar" and insisted he had nothing to do with the expose.
He added: "He has proven himself to be a world class liar and now rather than seeking help he is looking to blame others. His assertion is categorically untrue from A to Z. I pray he gets the help that he needs and I believe that it is him behind all of these stories to distract from his own failure to get help."
Meanwhile, Harvey - whose wife Georgina Chapman has left him in the wake of the allegations - is reportedly planning to fight back against his dismissal from The Weinstein Company.
Sources told The Blast the movie mogul's contract has specific guidelines around the protocol for allegations of misconduct, and it specifically states he cannot be dismissed for any accusations of sexual harassment made prior to 2015, which includes the claims currently made against him by the likes of Gwyneth Paltrow and Ashley Judd.
According to the outlet, Harvey is adamant his contract states there must be new allegations and a specific mediation based on those claims in order for him to be fired, and his lawyer has called the board of the company to highlight this.
Sources claim The Weinstein Company were "well aware" of all previous allegations and settlements and even launched internal investigations which found he had done nothing worthy of termination, and so they are contractually barred from punishing him now.
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