Rights groups decry Greek investigation into migrant shipwreck that left more than 500 dead

Human Rights Watch and Amnesty International claim that authorities failed to mobilise appropriate resources', while Greece says the ship's crew refused assistance

Human rights groups have deplored the lack of progress made by Greek authorities in their investigation into the controversial circumstances in which a migrant ship sank off the Peloponnese - leaving more than 500 dead - in one of the Mediterranean's worst ever boat disasters.

Human Rights Watch (HRW) and Amnesty International claim there are credible allegations that the Hellenic Coast Guard's actions and omissions" contributed to the 14 June shipwreck.