Massoud Setayeshi said the Judiciary will announce the results once the investigation is complete.
He added that the judicial officials are doing their job painstakingly.
Setayeshi also expressed regret over the attack on the Azeri embassy.
The attack on the Azeri embassy happened on January 27. The attacker was armed with a Klashnikov rifle and killed an embassy staffer and wounded two others after entering the embassy building.
Immediately after the attack, Azerbaijan vacated the embassy and has thus far refrained from returning its diplomatic staff.
Azerbaijan has however said it will not close its consulate general in the Iranian city of Tabriz.
The assailant said he did the attack because the Azerbaijani embassy ignored his requests for information about his wife, an Azeri national, who had earlier gone to the Azerbaijan Republic.
