Matthew McConaughey was ''disgusted'' when he first read the script for 'Killer Joe'.
The 42-year-old actor was initially reluctant to appear in the film - in which he plays the titular killer who befriends a young man who wants his mother murdered for her life insurance - until he read the story a second time and realised how funny it is.
He told Total Film magazine: ''When I first read the script, I was kind of disgusted. I just felt dirty. I didn't want to be around it.
''And then I talked to somebody whose opinion I trust and he said, 'Dude, it's hilarious! Read it again, man.'
''I went back and read it again with my funny bone alive and I found some of the humour among this character who's also deadly and a predator.''
Matthew was glad he agreed to star in the film because he had such a good time working with director William Friedkin.
He said: ''He usually does one take. Sometimes two. It was a ball. I don't wanna be up there thinking about what I'm gonna do, on the day, or right before the scene; I wanna have that work done before so I can just rip it.
''I don't want to leave the set. I don't even wanna have lunch a lot of the time. I don't wanna have the outside world interrupting me, getting in my eyeline, getting in my ear.''