Nicole Kidman sent "provocative" text messages to land her role
The director was reluctant to cast such a big-name actress in the low-budget movie - which sees Zac Efron and Matthew McConaughey play two brothers investigating the case of a death row inmate played by John Cusack - so Nicole went to extreme lengths to get him to agree to cast her as a sex-crazed woman obsessed with marrying a convicted killer.
She explained: "Lee said, `Look, we`ve got no money, you`re going to have to do your own hair and make-up.
"So I actually went into my bathroom and I got out the fake tan and put on fake eyelashes and got a hairpiece thing that was platinum, threw it all on and texted a photo to Lee in all these different provocative positions. That`s how it came together.
"What he sent back I can`t say, but it was a thumbs up."
Zac also enjoyed appearing in the movie because he was "in love" with his co-star.
Speaking at the Cannes Film Festival at a press conference for the film, he said: "I have been in love with her for a long time, since `Moulin Rouge!`. It was the best opportunity in the world for me, and I loved every moment."
And Lee was pleased with his cast - particularly a scene where Zac is out in the rain in just his underwear.
The director joked: "He`s a good-looking guy. And I`m gay. What do you want?"