Rebel Wilson Trashes Billionaire She Says Is Funding 4 Lawsuits Against Her

Rebel Wilson says she's dealing with multiple lawsuits ... and now she's firing back at the man she says is funding them.

Rebel went OFF in a series of posts on her Instagram Stories, slamming billionaire Sir Len Blavatnik, alleging he neglected to help her when she called out what she deemed to be bad behavior on set.

Remember ... Gregor Cameron, Vince Holden, and Amanda Ghost -- producers on Rebel's directorial debut "The Deb" -- filed a defamation lawsuit against Rebel after she claimed they embezzled $900,000 from the film's budget and said Ghost sexually harassed the film's lead actress, Charlotte MacInnes. Sources close to Ghost adamantly deny these claims.

According to several reports, MacInnes has publicly refuted Rebel's claim she was sexually harassed ... and a judge reportedly dismissed many of Wilson's counterclaims against the producers.

Now, Rebel says she flew to New York and asked Blavatnik for help with "the struggles I had with the people that worked for him: Amanda Ghost, Gregor Cameron, and Vince Holden," and she "sincerely thought he would do something about it."

She claims he instead used his money to fund "four lawsuits across two continents against me." A source says it's actually three lawsuits, not four.

Rebel says she also saw his name pop up in the Epstein Files ... sharing an email which appears to show Jeffrey Epstein asking someone to reach out to Blavatnik to give one of Epstein's friends a job. To be clear, Blavatnik is not accused of doing anything illegal or improper related to the email.

Bottom line ... this fight is getting nastier by the minute, so stay tuned!