He wasn't detained, but arrested as unknown foreigner in an illegal gathering. When police informed me a man's arrested who claims to be UK Amb, I said IMPOSSIBLE! only after my phone conversation w him I identified, out of big surprise, that it's him. 15 min later he was free. pic.twitter.com/VjuZxN1oTN

— Seyed Abbas Araghchi (@araghchi) January 12, 2020