
'It has been three months since the thirteen activists were taken to custody,' read the letter.
The prosecutor of Tehran has accused the detainees of espionage.
The letter has also asked that the findings of a committe which has been formed in this regard be published.
President Rouhani ordered a four-member committee two months ago to examine the situation and report to the public.
9417**1771
Follow us on Twitter @IrnaEnglish