Left, Scott J. Ferrell/Congressional Quarterly, via Getty Images; Gawker.com

Read the final version of this article that ran in Thursday’s newspaper.

Representative Chris Lee of New York, caught in the midst of a scandal involving a shirtless photo he reportedly e-mailed to a woman, has stepped down, according to a senior Congressional official.

Mr. Lee, a two-term Republican who is married, notified John A. Boehner, the Republican speaker of the House, of his decision in a letter he sent Wednesday afternoon after the scandal erupted.

Mr. Lee’s office released a statement late Wednesday in which he asks for forgiveness. “I regret the harm that my actions have caused my family, my staff and my constituents,’’ he said. “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.’’

Mr. Lee won his district, located in Western New York, in 2008, when he ran in place of Thomas Reynolds, who had announced his retirement.

Last year, another upstate New York congressman, Eric J. Massa, a Democrat, resigned amid accusations that he had groped a male aide.

Mr. Lee’s decision to step down came after a photo of him without a shirt appeared on Gawker along with e-mail exchanges that reportedly took place between him and a 34-year-old woman from Maryland who had placed a personal notice in the “women seeking men” section of Craigslist. The woman’s posting complained about the lack of attractive men on the Web site: “Will someone prove to me not all CL men look like toads?”

Mr. Lee responded, saying he was a lobbyist and a “fit fun classy guy.” He describes himself as 39 (he is 46) and divorced and writes, “I promise not to disappoint.”

When the woman asks if he routinely sends shirtless photos of himself to women on Craigslist, Mr. Lee responds, “Sorry, it’s all I had.” They later exchange e-mails discussing unsatisfying dates with others, and Mr. Lee mentions a woman who did not live up to her description. “She was not as advertised,” he says.

The woman told Gawker that she cut off communication after searching for Mr. Lee online and concluding that he had lied about his age and occupation.