"Big Brother" contestant Spencer Clawson of Conway, Arkansas just learned a valuable lesson about child porn ... don't even joke about it.

The show has been under fire all summer for things some of the contestants have said. At least two of them have lost their jobs in the real world because of insensitive racial or ethic remarks made in the Big Brother house.  The comments made this week by Clawson are now drawing the attention of police.  He is joking when he talks to some other contestants about pornography, saying, "I like to b*** **f to child porn. Did I ever tell y'all about that? I love it. ******* *** to child porn is my favorite thing there is."  It didn't end there. He said later: "I love it when they're around three or four years old. My favorite ones are when you can tell they're in a basement."

Conway Arkansas Police Chief AJ Gary says his department has been alerted by Clawson's comments and his officers moved in to investigate, but says at this time "we haven't found that any criminal act was committed."