Three more actors have joined the cast of Justin Timberlake's upcoming movie.

Filming has just begun on Edison, a crime thriller which stars Timberlake as a journalist who uncovers a group of corrupt policemen.

Already aboard the cast are Kevin Spacey, LL Cool J and Morgan Freeman. Piper Perabo was confirmed as the lead female at the weekend.

The three new signings include Cary Elwes (The Princess Bride), who will play a district attorney; Dylan McDermott (Miracle on 34th Street) as a bent policeman; and John Heard (Pollock), who will star as the head of an elite police unit.