Someone on a media conference call Tuesday called Congressman Tim Walz a "f---ing faggot."

The Mankato Democrat wasn't on the line to hear the anti-gay slur; in fact, he ran about five minutes late to his own availability, following a trip to Afghanistan. Before Walz came on the line, someone said, "Come on Walz, you f---ing faggot," according to his staff and two reporters who were on the call.

Meredith Salsbery, Walz's district communications director, says she doesn't know who made the offensive remark, though the voice was clearly a man's. She said participants did not have to identify themselves on the call — which was publicized via a media list emailed to traditional journalists, radio hosts and bloggers.

Two reporters on the call, the Rochester Post-Bulletin's Heather J. Carlson and Star Tribune's Jill Burcum, said they couldn't identify the person, either. So for now, it's a guessing game.

Whoever made the offensive remark didn't repeat his act; Salsbery says when Walz joined the call, the questions were professional and appropriate.

"It was a unique event," says Salsbery, who has worked for Walz since 2005. "A few reporters contacted me afterward to say it was totally inappropriate, not representative, and they did not enjoy hearing it."

There's an outside chance the utterer wasn't in the media; anyone could call in to the 800 number and join with the appropriate access code. Salsbery acknowledges her email instructions could've been forwarded to someone outside the profession, though that possibility seems remote.