Europe’s top human rights watchdog has urged Greece to end pushbacks of asylum-seekers on its borders, a practice that Athens denies carrying out.

In a letter to Greek ministers dated May 3 and published on Wednesday, the Council of Europe’s Human Rights Commissioner said there had been “numerous credible allegations” since at least 2017 of asylum-seekers illegally returned to Turkey or left adrift at sea but that Athens had simply dismissed them.

UNHCR, the United Nations’ refugee agency, has also gathered information pointing to several dozen pushbacks since January 2020, said the letter from Commissioner Dunja Mijatovic.

“I urge you (Greece) to put an end to these practices and to ensure that independent and effective investigations are carried out into all allegations of pushbacks and of ill-treatment by members of security forces,” Mijatovic said.

The Council of Europe is guardian of the European Convention on Human Rights and creator of the European Court of Human Rights.

In a response also published by Mijatovic’s office, Greece said it had investigated the allegations and found them “largely unsubstantiated”.

“The actions taken by the Greek authorities, at our sea borders, are being carried out in full compliance with the country’s international obligations,” Greek ministers were quoted as saying in their response to the Council.

They said Greece had rescued thousands of people since the start of Europe’s migrant crisis in 2015 and officers had to do their job “against the backdrop of an unfavourable environment of intended misleading information emanating in most cases from the smugglers’ networks”.

Mijatovic also said that living conditions in Greece’s overcrowded island camps remained “substandard”.

Speaking to Reuters, she cited the case of a 28-year-old Somali man on the island of Chios last week who had died of a pulmonary condition and whose body was marked by suspected rat bites.

“This is a tragic illustration of the horrific conditions in which thousands of people have been living for years on the Greek Aegean islands,” Mijatovic said.