Paramount is investigating claims Sylvester Stallone mocked extras on the set of "Tulsa King," a source close to the show confirmed to Fox News Digital. The comedy-drama series is facing allegations of a "toxic environment," which reportedly led to the resignation of casting director Rose Locke. While filming season 2 of the Paramount series, Stallone and director Craig Zisk both allegedly made disparaging remarks about the physical appearance of background actors.