Tokyo said on Wednesday that a Japanese national had been detained in Tehran and that it had “strongly demanded” Iranian authorities swiftly release the person.
Speaking at a daily briefing, Deputy Chief Cabinet Secretary Masanao Ozaki said the person was detained on Jan. 20 but gave no further details.
Iran International, a Persian-language satellite television channel and multilingual digital news operation based in London, reported earlier that a senior director of the Tehran bureau of Japanese public broadcaster NHK has been arrested and transferred to Evin Prison, citing people familiar with the matter.
Radio Free Europe/Radio Liberty identified the journalist as Shinnosuke Kawashima in a report citing two sources.

AloJapan.com