Mortimer, Braga, Santoro and a slew of Mamet favorites also sign on

The cast of David Mamet's already unusual martial arts drama has gotten just a bit stranger with Tim Allen snagging a key role.

Production on the Sony Pictures Classics project "Redbelt" will begin next month in Los Angeles with Chiwetel Ejiofor taking the lead role.

The "Dirty Pretty Things" star has been training with Brazilian jiu-jitsu masters from the Gracie family to play a pure martial arts practitioner who gets drawn into underground ultimate fighting matches after he runs afoul of some deals in the movie business.

Allen, last seen in the family smash "Wild Hogs," will play a troubled action star who meets up with the master after losing a street fight, this according to Variety.

Other recent credits for Allen include "Zoom," "The Shaggy Dog" and "The Santa Clause 3."

In addition to Ejiofor and Allen, the eclectic cast will include Emily Mortimer ("30 Rock," "Match Point"), Alice Braga ("City of God"), Rodrigo Santoro ("Lost," "300") and Mamet favorites Joe Mantegna, Ricky Jay, David Paymer and Rebecca Pidgeon.

The trade paper adds that a variety of mixed martial arts fighters and artist, including Randy Couture, John Machado, Danny Inosanto, Enson Inoue and Ray Mancini, will appear in the movie as well.

Consider us intrigued.