Maina Kiai, a human rights activist with the Kenya Human Rights Commission was on Sunday morning detained at JKIA.
Immigration officers are said to have demanded for his travel clearance yet he was not a government official.
Kiai missed his 7.50 am flight because the immigration officials could not stamp his passport.
Nancy Ng’ang’a, the immigration supervisor at the airport did not say why Maina was detained and needed clearance.
KHRC was on Monday deregistered by the executive director of the NGO Board, Fazul Mahamed citing misappropriation of 1.2 billion and 100 million in unpaid taxes.
Mr Kiai was later on set free.