A tearful US congressman today admitted sending a lewd photo of his underwear-clad crotch to a young woman over Twitter and then lying repeatedly to protect himself.
However, he refused to resign even as Democratic leader Nancy Pelosi called for an investigation into whether he broke the rules.
The extraordinary confession at a packed Manhattan news conference was a remarkable turn for Anthony Weiner, who conceded to a "hugely regrettable" lapse in judgment.
House Democratic leaders tersely expressed disappointment and embarrassment, reflecting an erosion of support for the 46-year-old New York congressman and casting doubts on whether Weiner could hold onto his House seat, let alone turn a once-promising political career into a 2013 bid for New York City mayor.
Weiner, an outspoken liberal congressman, insisted he had done nothing wrong and said he would fully cooperate with a House inquiry.
"People who draw conclusions about me are free to do so," Weiner said. "I've worked for the people of my district for 13 years and in politics for 20 years and I hope they see fit to see this in the light that it is."
But in a new twist, the married Weiner also acknowledged he had engaged in inappropriate contact with six women over three years through social networking sites like Twitter and Facebook and over the phone.
He said he had never met or had a physical relationship with any of the women and was not even sure of their ages. He also said he had never had sex outside of his marriage.
Last July, Weiner married Huma Abedin, a top aide to Secretary of State Hillary Clinton, with former President Bill Clinton officiating. Before his marriage, Weiner had been known as one of New York's most eligible bachelors.
The news conference, unusually blunt even by New York standards, went on nearly half an hour and capped a week of double-entendre, tabloid-headlines and late-night jokesters' snide comments. The word 'weiner' is also used for a type of sausage, and as a slang term for p***s.
Weiner said over and over that he had made "terrible mistakes" and done "a very dumb thing" for which he alone bore responsibility, and he apologised repeatedly to his wife.
Abedin did not attend his news conference, but Weiner said they would not be separating over the scandal.
Among the women Weiner contacted, Meagan Broussard (26), said that he had "friended" her on Facebook after she commented on one of his speeches posted online on April 20. They exchanged more than 100 messages, and Weiner constantly tried to steer the conversation toward sex.
"I don't think he's a bad guy. I think he's got issues just like everybody else," she said.
The scandal began more than a week ago when a website reported that a photo of a man's crotch had been sent from Weiner's Twitter account to a female college student in Seattle. For days, Weiner claimed that he hadn't sent the photo and that he was the victim of a hacker.