Journalist Larry Matthews says he was researching a story on the explosion of child pornography in cyberspace when he logged into Internet chat groups and received and sent images depicting children in sexually explicit situations.

Story or no story, federal prosecutors say it's still child pornography and what Matthews did is illegal. The case has spurred a debate over the freedom of the press and government controls on information, and Matthews could end up in prison.Matthews, 54, and media organizations maintain he has a First Amendment right to do research on a controversial subject.

"This is a social problem," Matthews said Monday in a telephone interview from his office in Washington, D.C. "Granted, it's a very disturbing and, in some cases, quite a disgusting problem, but does that mean we can't do our own investigation to find out about it?"

Prosecutors say the law makes no exceptions for journalists or anyone else. They also say they don't believe Matthews' interest was merely professional.