Question about Cambodian law regarding religion/christianity?

I have a friend thats going on a trip to Cambodia for church to teach others about God. Basically a bunch of people from her church are going and what there going to do is smuggle bibles into Cambodia by hiding the bibles under articles of clothing in their suitcases then their going to meet with underground church officials in Cambodia to discuss how to approach people. My question is under Cambodian law what would happen if my friend or if any of the other people got caught? What is Cambodian law regarding religion or Christianity? My friend is a little nervous and I'm a little worried too!