A person with dual nationality was among the hundreds of people arrested during recent anti-government protests in Iran, a judicial official said on Sunday.
"As far as I was able to find out, we had a dual national arrested and this person had been taking pictures and filming," judiciary spokesman Gholamhossein Mohseni Ejei told a weekly news conference
He gave no further details, but earlier this month another judicial official had said a European citizen was arrested during anti-government protests in Borujerd county in western Iran, without specifying their nationality.
The official accused the detainee of having been "trained by European intelligence services ... leading the rioters".
At least 22 people died and hundreds were arrested in the anti-government demonstrations that began in late December. The protests, the most widespread in Iran since 2009, were initially sparked by anger at the weak economy and official corruption, but escalated rapidly, with some protesters calling for the overthrow of the government.
Mr Mohseni Ejei said 55 people were still being detained in Tehran while some of the 400 held across the country were released on Saturday and Sunday.
A reformist Iranian MP, Mahmoud Sadeghi, said last week that about 3,700 people had been arrested in connection with the protests.
Iran restored access to the messaging app Telegram on Saturday after blocking the popular service to prevent the protests from spreading. It restored access to the picture-sharing site Instagram last week. Pictures and videos of the protests were often posted on social media to encourage more people to take part.