The statues were not 'effectively stolen' by Lord Elgin. He was given permission to record them and take plaster casts; marble that fell from buildings was then burned to extract lime for building, so he sought and was given, permission to remove them to Malta by an official edict from the Sultan of the Ottoman Empire, the civil governor of Athens and also the military commander, and again in 1810,
An investigation by a House of Commons select committee in 1816 cleared Elgin of removing the marbles illegally, done publicly 'before the whole world, local authorities and the Turkish Government. Elgin restored these marbles and saved them from destruction and the local population who would have destroyed them.
They were not looted, as were various other artefacts in Britain and other countries but removed legitimately.