Vaiko and others were lodged at a nearby marriage hall after being arrested, police said.
The MDMK leader had announced staging a picketing of the special camp at Poonamallee demanding release of the inmates lodged there besides the one at Chengalpattu and moving them to normal camps.
Alleging that the special camps acted as "detention camps," he had demanded that the Sri Lankan Tamils lodged there be released on humanitarian grounds.