The Iranian judiciary says a Swedish citizen is detained in Iran on suspicion of espionage, adding that he might also face other charges.

In a televised news conference on Tuesday, judiciary spokesperson Masoud Setayeshi said the Swedish national was arrested on April 17 but the case is still under investigation. 

“A number of documents were discovered from the detainee and are being investigated, and the preliminary investigation is confidential. Based on our clues, another charge may be brought against the suspect,” he said. 

Iran’s Intelligence Ministry said late in July that it has arrested a Swedish citizen in Iran on charges of espionage. The suspect, whose identity remains unknown, had been under surveillance by the ministry during several previous trips to Iran because of "suspicious behavior," including contacts with "European and non-European suspects who were under surveillance in Iran.”

The ministry added the suspect visited different cities across Iran which are not typical tourist destinations, and that the Swedish person had also travelled to Israel before visiting Iran.

The arrest was announced as Iran has “strongly condemned” a Swedish court’s sentencing of former Iranian jailor Hamid Nouri to life imprisonment over executions of political prisoners in 1988.

Late in June, the Swedish Ministry of Foreign Affairs advised its citizens against traveling to the Islamic Republic due to security risks to foreigners.

Tehran is already holding hostage Iranian-Swedish academic Ahmadreza Djalali, who is on death row.

Iran has been accused of wrongfully detaining foreign and dual nationals on trumped up charges, effectively as hostages to extract concessions from Western governments.