A naval court in Greece has charged 17 coastguards over the deadliest migrant boat disaster in the Mediterranean Sea for a decade.

Up to 650 people were feared to have drowned when the overcrowded Adriana fishing vessel sank near Pylos, off the Greek coast, in the early hours of 14 June 2023.

Survivors later told the BBC that Greek coastguards had caused their boat to capsize in a botched attempt to tow it and then silenced witnesses.

“It has taken us two years just for these charges to come, even though so many people witnessed what happened,” one of the survivors said on Monday.

The Greek authorities have always denied the claims against them.

The Deputy Prosecutor of the Piraeus Naval Court has found that 17 members of the Hellenic Coast Guard should face criminal charges.

Among them is the captain of the coastguard ship, the LS-920, who is charged with “causing a shipwreck”, leading to the deaths of “at least 82 people”.

This corresponds to the number of bodies recovered, although it is thought as many as an additional 500 people drowned, including women and children who were all below deck.

The disaster occurred in international waters but within Greece’s rescue zone.

The then-Chief of the Coast Guard and the Supervisor of the National Search and Rescue Coordination Centre in Piraeus are among four officials charged with “exposing others to danger”.

The captain of the LS-920 is also charged with “dangerous interference of maritime transport” as well as a “failure to provide assistance” to the migrant boat.

The crew of the ship are charged for “simple complicity” in all the acts allegedly committed by the captain.

A coastguard ship had been monitoring the Adriana for 15 hours before it sank.

It had left Libya for Italy with an estimated 750 people on board. Only 104 of them are known to have survived.

We have been investigating since the day of the disaster and our series of findings has cast serious doubt on the official Greek version of events.

Within a week, we obtained shipping data which challenged the claim the migrant boat had not been in trouble and so did not need to be rescued.

A month later, survivors told us the coastguard had caused their boat to sink in a disastrous effort to tow it and then forced witnesses to stay silent.

Last year, a case against nine Egyptians was thrown out, amid claims they had been scapegoated by the Greek authorities.

Earlier this year, audio recordings emerged which further challenged the official Greek version of events.

We first met Syrian refugees, who we called Ahmad and Musaab to protect their identities, a month after the disaster.

They said they each paid $4,500 (£3,480) for a spot on the boat.

The younger brother of Ahmad – a Syrian now living in Germany – was also on board and did not survive.

Musaab described to us the moment when – he alleged – the Greek coastguards caused their boat to sink.

“They attached a rope from the left,” he said. “Everyone moved to the right side of our boat to balance it. The Greek vessel moved off quickly causing our boat to flip. They kept dragging it for quite a distance.”

The men claimed that once on land, in the port of Kalamata, the coastguard told survivors to “shut up” when they started to talk about how the Greek authorities had caused the disaster.

“When people replied by saying the Greek coastguard was the cause, the official in charge of the questioning asked the interpreter to tell the interviewee to stop talking,” Ahmad said.

He said officials shouted: “You have survived death. Stop talking about the incident Don’t ask more questions about it.”

On Monday, Ahmad said he felt vindicated by the charges that had been brought.

“I’m very happy they are eventually being held accountable for all that they have committed, but until I see them in prison nothing has been done yet,” he said.

“To be honest, the Greek legal system is very unreliable.”

The joint legal team representing survivors and victims of the disaster said the decision to pursue a case against the 17 coastguards was a big step forward towards justice being done.

In a statement it said: “Almost two years after the Pylos shipwreck, the prosecution and referral to main investigation for felonies of 17 members of the Coast Guard, including senior officers of its leadership, constitutes a substantial and self-evident development in the course of vindication of the victims and the delivery of justice.”

It is understood the 17 men who have now been charged will be questioned in the coming weeks by the Deputy Prosecutor of the Piraeus Naval Court.

The court will then decide whether to send them to full trial or dismiss the charges.

It is not immediately clear what punishment the coastguards could receive if found guilty.

Greece has previously told the BBC its Coast Guard fully respects human rights and has rescued more than 250,000 people at sea in the past decade.