A former Iranian nuclear negotiator has been charged with giving classified information to the British embassy, the Iranian intelligence minister has said.
Mousavian is closely tied to a rival of President Mahmoud Ahmadinejad
Hossein Mousavian was detained and bailed in May over the allegations.
Mr Mousavian is close to former President Hashemi Rafsanjani, a leading rival to President Mahmoud Ahmadinejad.
In October, chief nuclear negotiator Ali Larijani resigned over reported differences with the president on the nuclear issue.
That was widely seen as a case of Mr Ahmadinejad tightening his hold on key posts in the Iranian administration.
Correspondents say the president wants to remove opponents of his economic and foreign policies, which have come under increasing criticism within Iran in recent months.
Intelligence Minister Gholam Hossein Mohseni Ejeie told the semi-official Fars news agency that Mr Mousavian was charged with giving information to foreigners including the British embassy.
"This accusation is proven in the eyes of the intelligence ministry," he said.
On Monday, Mr Ahmadinejad denounced as "traitors" those in Iran who have criticised its nuclear programme, state media have reported.
He went on to say that his critics had pressured a judge "to acquit a suspect for spying".
This was assumed to be a reference to Mr Mousavian.
Also on Wednesday Iran's parliament approved Mr Ahmadinejad's nominees for ministers of oil and industry.
The acting oil minister, Gholamhossein Nozari, was confirmed in his post, as was Ali Akbar Mehrabian as industry minister.