Gwyneth Paltrow and Ewan McGregor are set to join the Johnny Depp vehicle, Mortdecai, the comic crime thriller based on the series of books by Kyril Bonfiglioli.

No word has been forthcoming on Paltrow and McGregor's likely roles, but the film – apparently based on the final Mortdecai novel, The Great Mortdecai Moustache Mystery, which was completed by satirist Craig Brown – will be directed by David Koepp (Premium Rush). Described as "an amoral Bertie Wooster with psychopathic tendencies", Charlie Mortdecai is an unscrupulous art dealer on the track of Nazi treasure.

Depp's participation in Mortdecai was announced earlier this month in the aftermath of the disappointing box-office returns for his most recent blockbuster, The Lone Ranger. He is currently working on the big-screen adaptation of the Sondheim musical Into the Woods, while but has dropped out of Barry Levinson's Whitey Bulger biopic, Black Mass.