I can well understand why a Tamil living in Sri Lanka might want to emigrate somewhere else. Years of civil war would surely have led to a desire for a more peaceful existence but that desire does not a refugee make.
Refugees must be people under threat of persecution if they remain in their native land and I have seen no convincing evidence that that is the case for Tamils in Sri Lanka now that the Tamil Tiger terrorists have been defeated. I would expect that when claims for refugee status are investigated they will be dismissed and the economic migrants returned to Sri Lanka.
That should put a quick stop to the people smuggling trade.