Iran claimed Monday afternoon that it had handed an imprisoned American accused of spying to the country's chief terror proxy group, Hezbollah, according to reports in the country's state-controlled press that have caught the attention of the U.S. State Department.

Iran's state-controlled press reported that Iran was making preparations to extradite Nizar Zakka, an imprisoned dual American and Lebanese national, whom Tehran accused of spying and sentenced to a prison term.

An "informed source" told Iran's Fars News Agency Monday that Zakka would be transferred to Hezbollah later in the day.

"This will be done in the next few hours," Fars quoted the source as saying. "Extradition of the American-Lebanese spy has been made only at the request and mediation of Hezbollah Secretary-General Seyed Hassan Nasrallah."

Tehran claims that no talks have been held with the U.S. or other parties regarding Zakka's imprisonment.

Zakka "has been freed and extradited, thanks to Nasrallah's mediation and the respect Tehran pays to him," Fars reported.

A U.S. State Department official declined to comment "at this time" on the reports, but said the agency is aware of the latest developments.