WASHINGTON — In a moment that will probably go down in the annals of how not to handle a crisis, Rep. Anthony Weiner, D-N.Y., insisted again on Wednesday that he was not the one who sent a suggestive photo from his Twitter account — but told NBC News that “I can’t say with certitude” whether the now-famous image was of his own crotch.

In a series of television interviews, Weiner attempted to tamp down the furor that began over the weekend when a waist-down photograph of a man in his underwear appeared briefly on his page on the social networking site. The tweet, which Weiner said he deleted when he saw it, was addressed to a college student who follows him on the service.

The questions regarding the incident continued into a fourth day.

As CNN showed the image on the screen, a puzzled Wolf Blitzer pressed Weiner: “You would know if this was your underpants . . .”

“I appreciate you continuing to flash that at me,” Weiner said in a tone that made it clear he didn’t.

Weiner insisted again that the episode was “a prank” and “a hoax.” But his responses —and lack of them — assured the controversy would continue.

He said that he has hired a lawyer and a security firm, which he did not name, to investigate the matter.

Could it happen to you?

Here’s what people can do to keep their social media accounts safe and secure, according to John Harrison, a group manager of security firm Symantec’s Security Response team:

• Look for advanced default settings offered by social networks.

• Use secure wireless networks

• Update security patches often

• Set up social media accounts to provide alerts when being accessed from a new device or location

• Don’t be predictable: Don’t use 1234 or your spouse’s name as your password.