The Department Of State Services has released the President of the Nigerian Labour Congress, Joe Ajaero, after earlier arresting and detaining him while trying to board a flight to the United Kingdom on Monday.
Mr Ajaero was detained for a period of 15 hours though details of allegations against him leading to the arrest and detention are still largely unknown.
He was released late on Monday night at about 11pm.
He had earlier had an encounter with the Intelligence Response Team of the Nigerian Police Force over allegations of Terrorism Financing and Others.
His international passport according to reports were however seized.