The Department of State for Security (DSS) has arrested the President of the Nigeria Labour Congress (NLC), Joe Ajaero.
Ajaero was arrested at the Nnamdi Azikiwe International Aiport in Abuja, on Monday on his way to the United Kingdom for an official assignment, the NLC said.
Head of Information of the NLC, Mr Benson Upah, confirmed the arrest to news men.
The NLC president was billed to attend the Trade Union Congress conference in London, which begins today.
Upah said the union does not know where Ajaero had been taken but he had sent a message saying it was the DSS that arrested him.
His arrest comes about a week after he honoured an invitation by the police over what the police say was an investigation into terrorism financing.