A spokesman for the Human Rights Commissioner, Navi Pillay, told the BBC the allegations were so serious that the fighting in Sri Lanka required an inquiry similar to that recently carried out into the Gaza conflict.

Earlier this week, a report prepared by the US state department documented incidents in the final months of the war which it said might constitute crimes against humanity.

It detailed allegations of military shelling of Tamils as well as charges of Tamil Tigers using civilians as human shields.

But Sri Lanka has rejected the report saying the accusations were unsubstantiated.