Days after Iran triumphed at the inaugural Asian Women's Futsal Championship in Malaysia, reports emerged that eight of the Iranian team were male.
In violation of FIFA rules, the players either had yet to complete a sex change or had suffered from sexual development disorders, Britain's Daily Telegraph reported, citing Iranian sources.
A report by an Iranian state television website said the women players had the physical strength of men and some had "male inclinations".
An official for FIFA rejected the claims of rule breaking, though she indicated some players had previously suffered medical conditions that affected their appearance.
"There are no gender concerns for women's futsal and football teams," Dr Zohreh Haratian, the governing body's appointee in Iran, told Shargh daily.
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"No scientific proof exists on these claims," she said, noting that all the players had been checked.
According to the rules, any players participating in overseas matches, should first go through gender verification by FIFA's medical representative, Haratian explained.
"Only then the player will be permitted to play in Asian or global matches. FIFA will respond to such accusations by foreign media," she said, naming Saudi Arabia's Al-Arabia and Britain's Sky News.
The allegations are not new, said Haratian, also the Head of Iran's Football Medical Assessment and Rehabilitation Center.
"In the past, a few of our female football players were accused of being bisexual," she continued, adding that in 2010, one player suffering "an inborn disease of adrenal glands" and looked liked a man but was actually a woman.
"When FIFA understood that their problem was inborn, it rejected the claims and issued permits for them to play in matches."