"I saw the picture and I don't remember him, but they didn't actually introduce themselves to me," said John Limbert, who heads the American Foreign Service Assn. in Washington, which represents about 26,000 active and retired U.S. diplomats.
"I heard what my colleagues said. They certainly seem certain and I respect their opinion, but I just don't remember that face. I can't look at him and say, 'I saw him there.' "
Another former hostage, Barry Rosen, said in an interview from New York that he had been taken away by the captors before one of the photos now being broadcast was taken.
"I have never seen him; I can't say one way or another" whether Ahmadinejad is the man others remember, he said.
Rosen said he became close friends during months of captivity with one of the other hostages, Dave Roeder, who has said he recognizes the new Iranian leader as one of the captors.
"If Dave says it, I believe it," Rosen said.
It is widely known that Ahmadinejad helped to plot the embassy's seizure in November 1979 and that he was a member of a student group called the Office to Foster Unity, which was initially formed to win support for Iran's new Islamic Revolution among skeptical university students.
In Tehran, two of Iran's most prominent former hostage takers said Thursday that Ahmadinejad was not among the students who stormed the U.S. Embassy. They said, however, that he had attended meetings at which students plotted the takeover.
"He was only there in the first couple of planning sessions," said Elaheh Mojarradi, a former hostage taker. "Not the actual event."
Mojarradi met her husband, Mohsen Mirdamadi, during the embassy takeover. For the couple, like many of their revolutionary colleagues, the embassy standoff was the beginning of a life of privilege and power. Mirdamadi became a prominent reformist lawmaker, head of the Iranian parliament's National Security and Foreign Policy Committee and a close aide to outgoing President Mohammad Khatami.
Massoumeh Ebtekar, who was the spokeswoman for the students, became vice president for the environment. She was the first woman in the Islamic Republic to be named to the presidential Cabinet.
The students eventually became voices of reform and moderation against Iran's hard-liners. As the decades passed, Mirdamadi and his wife evolved into outspoken critics of Iran's hard-line clerics. Mirdamadi was the director of a reformist newspaper, Norouz, which was shut down by the regime.
Special correspondent Nahid Siamdoust in Tehran and Times staff writer Megan K. Stack in Cairo contributed to this report.