Survivors of a migrant shipwreck off Greece in June, in which hundreds died, filed a lawsuit against the Greek authorities on Thursday, accusing them of violating their duty to protect the lives of the people on board the vessel.

The overcrowded fishing trawler said to be carrying between 400-750 people from Pakistan, Syria and Egypt sank in international waters off Greece on its way to Italy from Libya. Some 104 men survived and authorities recovered only 82 bodies.

Survivors have recounted hellish conditions above and below deck, with no food or water and a disastrous attempt by the Greek coast guard to tow the vessel which capsized, according to interviews and evidence seen by Reuters.

The Greek coastguard and government have said they were monitoring the vessel for hours and no attempt was made to tow the boat which overturned when the coastguard was about 70 metres away.

A judicial investigation into the causes of the disaster is under way and could take more than a year to be completed.

On Thursday, 40 survivors filed a lawsuit complaining that “Greek authorities failed to intervene immediately and organize an appropriate operation in time to rescue those on board,” a statement by the Hellenic Leage for Human Rights, one of their representatives, said.

They say the vessel was “clearly unseaworthy” and also call for “an immediate, thorough and credible investigation” into the causes of the deadliest boat disaster in the Mediterranean in recent years.

Lawyers representing families of the missing have filed a request to judicial authorities investigating the case for the boat to be retrieved.