After a combative news conference on Tuesday in which Weiner refused to answer any questions about the incident, the Democratic lawmaker spent Wednesday in a series of media interviews trying to explain the situation. But some answers - and his attempts at humor - only stirred up the situation further.
"We know for sure I didn't send this photograph," the seven-term congressman told reporters in the Capitol. But he told MSNBC he "can't say with certitude" that the waist-down photo showing a man's bulging underpants wasn't him.
Pressed by reporters about whether it was him in the offending photo, Weiner said: "We don't know where the photograph came from. We don't know for sure what's on it."
And then the colorful congressman couldn't resist several double entendres, explaining why he didn't report the alleged hacking to Capitol Police.
"I'm not sure I want to put national, federal resources into trying to figure out who posted a picture on Weiner's website, uh, whatever. I'm not really sure it rises, no pun intended, to that level."
Later, he quipped that maybe the alleged hacking was just "the point of al-Qaeda's sword."
Despite his denial, questions still lingered about the incident.
Weiner said he had hired a private security firm to investigate the alleged hacking and an attorney to advise him on what civil or criminal actions should be taken.
"If it turns out there's something larger going on here, we'll take the requisite steps," he told reporters when asked why he hadn't asked for a police probe.
There were also questions about why the congressman, married recently to an aide to Secretary of State Hillary Rodham Clinton, was following the female college student on Twitter.
Chris Lehane, a veteran Democratic strategist, said he was surprised Weiner had not been more forthcoming sooner.
"You aren't going to get by on a story of this nature without giving a comprehensive explanation," Lehane said. "The only way you can put out a fire that has been ignited with bad information is to douse it with good information."
Democratic strategist Steve McMahon said the congressman botched the first rule of crisis communications: getting out the facts as soon as possible.
"His answers have raised more questions than they've resolved," McMahon said. "I'm amazed somebody as smart and media savvy as he is can't see the impact of how he's handled it."
Weiner's New York congressional delegation colleagues weren't saying much about the situation on Wednesday.
"This appears to be a law enforcement matter," Rep. Peter King, R-N.Y., said in a statement.
The sexually suggestive photo was posted Friday and sent to the student in Seattle. The tweet of the lewd photo first was reported Saturday by BigGovernment.com, a website run by conservative commentator Andrew Breitbart.
Breitbart is also known for posting a video of an Agriculture Department employee, Shirley Sherrod, giving a speech that when edited by Breitbart, made it appear that she was making racist comments.
The photo on Weiner's account was quickly deleted, but it set off a torrent of speculative buzz.
Weiner told reporters he had been tweeting about the National Hockey League playoffs when he spotted the offending tweet.
"I saw it," Weiner told reporters at the Capitol. "I deleted it."
Weiner said he misjudged the furor the photo would cause.
Weiner has not explained why he was following the student on Twitter, one of just 198 people he follows on the social media site. Weiner is one of the more prolific tweeters in Congress and he has more than 50,000 followers, a number that grew over the past two days.
The woman has been identified by media outlets as Gennette Cordova. Despite multiple calls to phone numbers and an email address for Cordova, she could not be reached for comment by The Associated Press.
Cordova told the New York Daily News that the offending photo was sent from a hacker who has "harassed me many times after the congressman followed me on Twitter a month or so ago."
Cordova also told the Daily News she never had met Weiner, and that there had "never been any inappropriate exchanges" between her and the congressman.
Cordova was back with a Twitter feed this week, scolding others for re-tweeting a link about "the other `young luscious girls' being followed by AW on Twitter, you should be ashamed."'
Weiner, 46, married Clinton aide Huma Abedin last July, with former President Bill Clinton officiating. Before that, Weiner had been known as one of New York's most eligible bachelors.
Weiner failed in a 2005 bid for the Democratic nomination for mayor of New York City, but is considered a likely front-runner in the race to succeed Mayor Michael Bloomberg when the mayor's third and final term ends in 2013.
Weiner is the third New York congressman in little over a year to be caught up in a sex scandal. Republican Rep. Chris Lee resigned earlier this year after shirtless photos he sent to a woman surfaced online. Democratic Rep. Eric Massa resigned in March 2010 amid a sexual harassment scandal.
Hackers have managed to take over celebrity Twitter accounts now and then, usually by guessing passwords. According to BigGovernment.com, the picture was stored on an account with Yfrog, a media-sharing site that allows users to tweet directly, bypassing Twitter.com.
Associated Press writers Beth Fouhy and Peter Svensson in New York contributed to this report.