Rodrigo Santoro joins the cast of 'I Love You, Phillip Morris'

"Lost" and "300" co-star Rodrigo Santoro will romance Jim Carrey in the prison comedy "I Love You, Phillip Morris."

Ewan McGregor co-stars in the film, which marks the directing debut of "Bad Santa" scribes Glenn Ficarra and John Requa.

Carrey plays Steven Russell, a frequently imprisoned conman with a genius IQ and a rather unusual personal life. Married and a father, Russell was doing a stint in jail for insurance fraud when he fell in love with his prison cell mate, Phillip Morris (McGregor). Russell is notorious for both the scope of his cons and his repeated successful (at least temporarily) prison escapes.

The script, by Ficarra and Requa, is based on the book by Steve McVicker, a crime reporter with the Houston Chronicle.

Santoro's exact role isn't described in the Hollywood Reporter, beyond the knowledge that his character will be another of Russell's lovers.

The trade also says that Leslie Mann is in place as Russell's wife.

Xerxes in "300" and Paulo on "Lost," Santoro's upcoming credits include "Redbelt" and Steven Soderbergh's two-part biopic "Che."