© Rex Features
According to Deadline, the Flight of the Conchords star has signed to play the role of Yaz in the sci-fi sequel.
Clement and Sacha Baron Cohen were both linked to the part in March.
The actor/musician joins Will Smith, Tommy Lee Jones and Josh Brolin in the picture, which is directed by Barry Sonnenfeld.
Men in Black III is scheduled to arrive in US cinemas on May 25, 2012.
