The report quoted lawyer Saeid Dehghan as saying Roland Marchal was detained on security charges in June while visiting Iran to see Iranian-French fellow academic Fariba Adelkhah. Iran disclosed in July the arrest of Adelkhah, a prominent anthropologist who holds dual French-Iranian nationality. Adelkhah often traveled to Iran for her research on post-revolutionary Iranian society.
Iran said she was arrested on espionage charges. France revealed earlier this month that Marchal had also been arrested. The revelation came after Iran rejected as "unacceptable" a call by France for the release of Adelkhah. Iran does not recognize dual nationality for its citizens.
Marchal was in Iran to celebrate the Muslim holiday of Eid al-Fitr that ends the holy month of Ramadan with Adelkhah when he was arrested, according to a statement from the African Studies Association in France.
Since Marchal's detention became public, academics around the world have demanded Iran release the two academics. The Paris university Sciences Po issued a statement calling the detentions "scandalous, appalling and arbitrary."
Dehghan, the lawyer, said he has visited both his clients twice. Their cases are currently under review at the office of the prosecutors dealing with security and espionage charges. "So far, neither of the cases has been sent to a court for trial," said the attorney.
Monday's ISNA report was the first mention in Iran of Marchal's arrest, after his detention was reported by the French newspaper Le Figaro earlier this month. The French consul in Iran has visited Marchal, a sub-Saharan Africa specialist at Sciences Po, multiple times in jail and is in touch with his family, according to French officials.
An association of researchers at Sciences Po and other institutions said in an October statement that colleagues had flagged the disappearance of Marchal and Adelkhah in Iran to French authorities on June 25.
Professor Richard Banegas at Sciences Po, who worked closely with Marchal, said he believed they were arrested around June 6. The scholars kept Marchal's imprisonment confidential at the recommendation of the foreign ministry, even after Adelkhah's detention became public.
Iran has also detained at least two other dual nationals: Iranian-British anthropologist Kameel Ahmady and Iranian-British national Nazanin Zaghari-Ratcliffe. They have been accused of spying and of links to foreign intelligence agencies.
Associated Press writer Claire Parker in Paris contributed to this report.