Operatives of the Department of State Services (DSS) have arrested Joe Ajaero, President of the Nigeria Labour Congress (NLC).
He was apprehended at the Nnamdi Azikiwe International Airport in Abuja.
Ajaero was on his way to the United Kingdom for a Trade Union Congress (TUC) conference when he was taken into custody.
Reports said that after his arrest, he was transferred to the National Intelligence Agency (NIA).
While the details of the arrest remain unclear, sources said it could be related to ongoing investigations into terrorism financing, cybercrime, subversion, conspiracy, and treasonable felony.
The situation has raised concerns about his alleged involvement with a British national, Andrew Wynne, accused of supporting protests aimed at destabilizing the administration of President Bola Tinubu.