Europe's tolerance of refugee abuse 'alarming'

Such violations were "now so frequent that they hardly register in the public consciousness," she added.

Mijatović spoke in a statement on Monday (19 June), following last week's sinking of a boat with up to 750 people on board.

Just 104 survivors have been found, making the incident, which took place at 2AM on 14 June in the Ionian Sea some 87km southwest of Pylos in Greece, one of the worst shipwrecks in modern times.

An Italian-led rescue operation also rescued hundreds of people over the past two days, according to Italian media.

But the Ionian sinking continues to pose hard questions on accountability and the role of the Greek coast guard.

Conservative Greek prime minister Kyriakos Mitsotakis fended off criticism of the rescue operation from opposition MPs and NGOs over the weekend, ahead of his re-election bid on 25 June.

He also blamed smugglers for what happened, echoing demands by the European Commission to intensify the crackdown on human-traffickers.

The Greek coast guard claims the boat was on a "steady course and speed" towards Italy and had refused aid.

It admits attaching a tow rope, but says this didn't cause the capsize.

The rope was merely used to "steady themselves, to approach, to see if they wanted any help", a coast-guard spokesman said.

But a BBC investigation has cast doubt on the official version of what really happened.

The BBC, based on tracking data provided by MarineTraffic, says the boat had in fact not moved for seven hours.

BBC testimonies collected from survivors also say the Greek coast guard attempted to tow the boat, which later capsized.

Another survivor told The Sunday Times newspaper that once the boat capsized, survivors were left in the water for at least three hours before rescue.

The Greek coast guard did nothing as people treaded water, he said.

"They just watched," he said. "They could have saved so many more."

A similar testimony was reported by La Repubblica, an Italian newspaper.

"They hooked us with the ropes, then gave a yank and the boat turned over," a survivor said.

A Greek investigation has since been launched.

But that probe will be held in secrecy, following a demand by Greece's supreme court prosecutor Isidoros Dogiakos.

And Dogiakos already stands accused of obstructing a separate investigation into the use of Pegasus spyware by the Greek government, making some MEPs sceptical about the due process.

"The calls for secrecy by general prosecutor Dogiakos and witnesses being kept incommunicado are worrying," said Dutch liberal MEP Sophie In't Veld, in a tweet.

For its part, the EU Commission told reporters on Monday that the Greek investigation should be "thorough and transparent."

Nine Egyptians have been arrested on suspicion of being people smugglers.

Among the survivors were reportedly 47 Syrians, 43 Egyptians, 12 Pakistanis and two Palestinians.