The characters of Barty Crouch, Igor Karkaroff, Amos Diggory and Barty Crouch Jr. have been confirmed for Harry Potter and the Goblet of Fire. The names, printed in a press release from Warner Bros., includes the full list of additions to the cast:
Joining the ensemble are several new cast members, led by esteemed actor Brendan Gleeson (Troy, Cold Mountain), who plays Hogwarts' new Defense Against the Dark Arts teacher Mad-Eye Moody. Frances De La Tour (The Cherry Orchard, Strike it Rich) plays the Headmistress of Beauxbatons Academy of Magic, Madame Maxime; Roger Lloyd-Pack (Vanity Fair, BBC TV's Only Fools and Horses) plays the Head of the Department of International Magical Cooperation, Barty Crouch; Pedja Bjelac (Eurotrip) plays Durmstrang Professor Igor Karkaroff; Jeff Rawle (Inspector Calls II, Baal, TV's Drop the Dead Donkey) plays Amos Diggory; and David Tennant (Bright Young Things) plays Barty Crouch Jr.
Update: Check out The Leaky Cauldron for some photos of the new additions HERE.
Thanks to Veritaserum for the tip.