"It certainly doesn't look familiar to me, but I don't want to say with certitude to you something that I don't know to be the certain truth," Weiner said at the time.
After more reports of online exchanges with other women surfaced, fellow Democrats encouraged Weiner to resign, which he ultimately did after confessing to the indiscretions.
In the run-up to his mayoral bid, which he launched in May, he said more photos could emerge.
"If reporters want to go and try to find more, I can't say they're not going to be able to find another picture, find another person who may want to come out on their own," he told RNN Television. "But I'm not going to contribute to that. The basics of the story are not going to change. It's behind me. It was a huge mistake."
Polls taken over the past several weeks have shown Weiner either leading his closest rival for the Democratic mayoral nomination, City Council Speaker Christine Quinn, or trailing her in second place.