The United States is pushing Iran to free "without delay" US citizen Amir Mirzai Hekmati, who confessed on state television that he had been sent to infiltrate Iranian intelligence services, Agence France Presse reported.
Hekmati, who is of Iranian descent and speaks both in English and Farsi, was born in Arizona.
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On Sunday, Iranian state television showed a clean-shaven man in his 20s who said he had a decade of intelligence training – and was told to obtain Iranian intelligence by offering information on US forces in neighboring Afghanistan, AFP reported.
A State Department spokeswoman said the US had requested access to Hekmati through the embassy of Switzerland, which operates as an intermediary between the countries, the BBC reported.
Hekmati's family denied their son was involved in espionage. His father, Ali Hekmati, told ABC News:
"My son is no spy. He is innocent. He's a good fellow, a good citizen, a good man ... These are all unfounded allegations and a bunch of lies."
It is understood that Hekmati's family first reported his detention in September, and the State Department has been offering consular assistance.
The Iranian television report said Hekmati joined the US Army in 2001 and received special training before being sent to Iran, the BBC reported.
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Ali Hekmati said his son joined the US marines in 2001 as an Arabic translator.
Tehran in May claimed to be holding as many as 30 CIA operatives.