The actor — who shot to fame through roles on the TV series Charmed and in the horror film Scream — had previously accused Weinstein of raping her in a hotel room at the Sundance Film Festival in 1997, which he denied.
McGowan said that as she was preparing to publish her memoir with details of the assault, Weinstein hired a team of lawyers and investigators to obtain a copy of the book and publicly discredit her.
The disgraced movie producer is currently serving a 23-year prison sentence after being convicted by a New York City jury last year of raping and sexually assaulting two women.