12:35 PM PT -- A rep for Harvey tells us, "No matter what derogatory things Bob Weinstein says about his brother, Harvey Weinstein believes his brother is his brother and does not believe his brother would leak his personnel file to the NYT." The rep continues, "Harvey is dealing with his family and is currently in counseling. These are his priorities."

Harvey Weinstein believes his own brother was responsible for his demise, and he has the proof in the form of a receipt ... but Bob Weinstein says Harvey's a "very sick man" who's slinging fake stories to deflect from his own misdeeds.

Sources connected to H.W. tell TMZ, Harvey firmly believes it was his brother Bob who fed The New York Times the information for its sexual harassment story. He believes it was a well-orchestrated plan by Bob to remove Harvey from the company he built.

Weinstein, we're told, firmly believes the entire board knew about his sexual harassment troubles for years. Our sources say 7 months ago Bob received Weinstein's entire personnel file which detailed a number of the claims, and he believes Bob leaked the file to The NY Times.

As for proof the file was sent, we're told Harvey Weinstein's people have a FedEx receipt which shows his brother got the material.

Bob Weinstein came out swinging, telling 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."

Bob goes on ... "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."