Updated 06:54 GMT
Another Tamil man was arrested by the Terrorism Investigation Department (TID), who accused him of plotting to restart the LTTE.
Father of two Sankaralingam Sasikaran, 30, was arrested on Monday evening in Kilinochchi and taken to the 2nd floor of the TID headquarters in Colombo, according to his wife.
Mr Sasikaran, originally from Sinnaoorani, Batticaloa, was living in Bharathipuram, Kilinochchi, where he was employed by a local NGO, which worked with war-affected households and providing education to children.
*This article was updated with more information and edited to correct the age of Mr Sasikaran and the location of his arrest.