WASHINGTON, June 30: Several Americans held hostage in the 1979 US Embassy takeover in Tehran generated a new controversy on Thursday when they claimed that Iran’s president-elect was a leader of the hostage-takers.

Mahmood Ahmadinejad has denied involvement in the hostage-taking, supported by at least one hostage who said he does not believe the Iranian president-elect was among the hostage-takers. Former hostage-takers also have said that Mr Mahmood was not among them.

The White House, however, has expressed ‘serious concern’, saying that the claim by former hostages raises ‘many questions’ about Mr Mahmood’s past.

In interviews to US media outlets, five former American hostages said they believe Iran’s President-elect Mahmoud Ahmadinejad was one of those who held them captive in the US embassy in Tehran for 444 days quarter of a century ago.

After watching coverage of Iran’s presidential election on television, four of the former hostages -– Chuck Scott, David Roeder, William J. Daugherty and Don A. Sharer -– exchanged e-mails and later told reporters that they came to the conclusion that Mr Mahmood was one of their Iranian captors.

A fifth ex-hostage, Kevin Hermening, said he reached the same conclusion as the four others after looking at the photos.

“He wasn’t a very nice fellow at the time. He called us pigs and dogs. He’s very hard-line, he’s a guy we are not going to get along with,” said Mr Sharer in an interview with ABC’s “Good Morning America” show.

Another former hostage, Paul Lewis, said he thought Ahmadinejad looked vaguely familiar when he saw a picture of him on the news last week, but the former Marine embassy guard said he could not be certain.

Mr Daugherty said he had ‘no doubts at all’ that Mr Mahmood was one of his hostage-takers.

“When your country is being humiliated and being embarrassed, the individuals that do that really stick in your mind. You don’t forget people who do things like that to you and your family and your country,” said Mr Daugherty.

Not everyone agrees. Former hostage and retired Air Force Col. Thomas E. Schaefer said he doesn’t recognize Mr Mahmood, by face or name, as one of his captors.

Several former students among the hostage-takers also said Mr Mahmood did not participate. And a close aide to Mr Mahmood denied the president-elect took part in the seizure of the embassy or in holding Americans hostage.

Militant students seized the US Embassy in Tehran on November 4, 1979, and held 52 Americans hostage for 444 days to protest Washington’s refusal to hand over the US-backed Shah for trial.

The Shah had fled Iran earlier that year after he was overthrown by the Islamic Revolution.

The White House said it was concerned about the implications of the former hostages’ statements and was looking into the claims.

“I think the news reports and statements from several former American hostages raise many questions about his past,” White House spokesman Scott McClellan said.