A Republican congressman from western New York announced his resignation Monday after a gossip website published a shirtless photo he sent to a woman who posted a Craigslist personal ad.

According to a report at Gawker, Rep. Chris Lee (R-NY) responded to an ad a 34-year-old woman posted to Craigslist's "women seeking men" section, sending her pictures of himself and claiming to be a 39-year-old, divorced lobbyist. Lee is married with one child and is 46 years old.

Lee's office confirmed to Gawker that it was his email address that was used to correspond with the woman.

"I regret the harm that my actions have caused my family, my staff and my constituents," Lee said in a statement circulated to the media. "I deeply and sincerely apologize to them all. I have made profound mistakes and I promise to work as hard as I can to seek their forgiveness."

Gawker reported that Lee responded quickly to a January 14 ad challenging "Craigslist men" to prove they don't all "look like toads."

Lee responded with a fully-dressed picture of himself and the comment, "I hope I'm not a toad."

When the woman responded with "Are you sure that's not a photo from a JCPenney ad?", Lee responded with "Here ... I just took one. I'm relaxing at home." That message was accompanied with a photo of Lee topless in front of a mirror, flexing his right arm.

Gawker noted that the conversation was "relatively banal" but his "support for 'Don't Ask, Don't Tell' and vote to reject federal abortion funding suggests a certain comfort with publicly scrutinizing others' sex lives."

Lee was first elected to New York's 26th congressional district, which includes parts of the suburbs of Buffalo and Rochester, in 2008. A special election to replace him hasn't been called yet.