The two-time Oscar winner's career collapsed in late 2017 after he was hit by a string of gay sexual misconduct allegations, but Spacey is now planning to return to acting by playing a detective who investigates a wrongly-accused paedophile in "L'uomo che disegno Dio" ("The Man Who Drew God").
The movie will also star Redgrave and be directed by her husband, Italian filmmaker Franco Nero, who will play a blind artist fighting allegations of sexual abuse, according to The Telegraph.
Confirming Spacey's involvement, Nero told ABC News, "I'm very happy Kevin agreed to participate in my film. I consider him a great actor and I can't wait to start the movie."
Representatives for Spacey, who previously denied all allegations of inappropriate behaviour, have yet to comment on the gig.
He last appeared onscreen in the 2018 box office flop "Billionaire Boys Club".
The casting news came after it's reported that the sexual assault case against the actor was expected to be dismissed as his accuser refused to reveal his identity.
U.S. District Judge Lewis Kaplan ruled that the male source known as C.D. had to publicly confirm his identity in order for the case against Spacey to proceed because interest in the case was "magnified" due to his allegations being levelled against a public figure.
But the accuser's lawyers explained he would not be revealing his name, "As we had previously informed the Court, C.D. believes he is unable to withstand the scrutiny and intrusion into his life if his identity is revealed in this matter."