The BBC World Service reporter’s social media accounts were probed despite him having travelled to Chicago’s O’Hare airport from London Heathrow while holding a British passport.
Four and a half hours later...
Hamedani then took the opportunity to highlight the plight of those who can’t travel under the ban.
The Foreign Office has since said it was told by the US that extra checks would be performed on UK citizens only if they were dual nationals travelling from one of seven counties, which are predominantly Muslim.
Hamedani told BBC Radio 5 Live’s Stephen Nolan: “So they took away my phone and they started searching and I saw the guy searching my Twitter account.
“So they were looking to find about any kind of political views, whether I’m supporting anybody – any kind of extremist idea or not.
“They also asked me questions about whether I have been trained by the military, if I had been trained in military bases in Iran or when was the last time I was back home in Iran.
“It wasn’t pleasant at all. To be honest with you, I was arrested back home in Iran in 2009 because I was working for the BBC and I felt the same this time.”
Hamedani, who landed at around 4.40pm UK time on Sunday and has rescinded his Iranian passport, said he was met by protesters after making it through security.
He said: “The very touching moment was when I came out of the whole thing, when I came out into the arrival hall, I have met more than 50 people, most of them American ... and they hugged me and they welcomed me and they were trying to say ‘this is not the real America, we are the real American people’.”
His ordeal came ahead of the Foreign Office saying Foreign Secretary Boris Johnson had been told by the US president’s team that Britons with dual nationalities would not be barred from entry.
Johnson was also told that heightened scrutiny for dual citizens would only apply to individuals travelling directly to the US from Iraq, Iran, Libya, Somalia, Sudan, Syria and Yemen.