Iran's former senior nuclear negotiator, Hossein Mousavian, has been charged with passing classified information to foreigners including to the British Embassy, the Iranian intelligence minister said Wednesday according to the official IRNA news agency.

"He has been informed of the charges that he has given the British Embassy information contrary to the security of the country," the news agency quoted Gholam Hossein Mohseni Ejehi as saying.

There was no word on when he would actually be put on trial.

Mousavian — who was the top nuclear negotiator under former reformist President Mohammad Khatami — was briefly detained in May, again on suspicion of espionage according to the semiofficial Fars news agency.

"From the viewpoint of the Intelligence Ministry, he is a criminal ... this is definite and provable. But the decision (on the case) rests with the judge," Fars quoted Ejehi as saying Wednesday.

On Monday, Iran's hard-line President Mahmoud Ahmadinejad blasted critics of his nuclear policies as "traitors" and accused them of spying for Iran's enemies, using his strongest rhetoric yet against domestic opponents and raising concerns of a possible crackdown.

But Ejehi named Mousavian directly, saying "influential persons have called the judge and tried to get him (Mousavian) acquitted."

Domestic criticism has lately mounted against the president over the nuclear issue, with Mousavian's successor, Hasan Rowhani, delivering an unusually sharp rebuke to Ahmadinejad last month, saying he was making more enemies for Iran with his policies.