Greek police have been hiring migrants to stop other foreigners from entering the country, a new investigation has reported. 

Internal police documents analysed by the BBC are said to show how guards have been ordered to recruit migrants by senior officers to push back incoming migrants at the Greece-Turkey land border since 2020.

The investigation also revealed allegations of violence, with witnesses reporting migrants being stripped, robbed, beaten and even sexually assaulted. 

The so-called mercenaries, who come from countries such as Pakistan, Syria and Afghanistan, are rewarded with cash and mobile devices looted from other migrants, as well as documents that will eventually allow them passage through Greece, claims suggest. 

Forcing migrants and asylum seekers back across international borders without due process is generally considered illegal under international law. 

But evidence gathered by the BBC allegedly shows migrants being mistreated at the border by other migrants before being pushed back towards Turkey. 

The broadcaster analysed a video from June 2023 that purportedly shows a group of migrants, who had just crossed into the Evros region, being attacked by masked men.

Other documents analysed by the broadcaster revealed how a border guard told a disciplinary hearing they had information that mercenaries had been raping female migrants. 

Meanwhile, two migrants and an ex-mercenary told the BBC about how they saw extreme violence by both mercenaries and Greek police, including people being violently beaten until they went unconscious. 

Separately, a female migrant, who was forced back to Turkey, claimed that two masked men demanded she hand over her phone before she was driven to the border in a van. 

She says a man then took off her daughter's nappy in the hunt for valuables, leaving her child screaming in fear.'

She also described how she saw a young man being beaten unconscious by masked men.

Another migrant told the BBC how he was among dozens of migrants who were loaded into a truck to be transported back out of Greece, describing how people were left suffocating and unable to breathe. 

They were then handed to a group of mercenaries who strip-searched them and then loaded them into dinghies halfway across the river, before pushing migrants into the river Evros.

The BBC also met a lawyer who had lodged a case at the European Court of Human Rights, on behalf of an Afghan woman who alleges she was raped by a masked man who spoke Farsi, just before a pushback in 2023. 

 A separate report by the Fundamental Rights Office, an independent investigator within Frontex, found that in one instance, between 10 and 20 'third-country nationals' had been acting under the instruction of Greek officers.

It also said they had subjected the migrants to physical and verbal abuse, including 'death and rape threats, intrusive and sexualised body searches,' as well as beating, stabbing and theft. 

The report said that the migrants were then forcibly transported back to Turkey, in violation of EU human rights law.

The Greek authorities, however, have denied that any migrants from this group were found in the area on that day. 

A police source also claimed that mercenaries were being used to push back as many people as possible, saying:  'There is no soldier, police officer or Frontex (EU border agency) officer serving here in Evros who does not know that pushbacks are taking place.'

Greece's Prime Minister told the BBC he was 'totally unaware' of the allegations that migrants were used for pushbacks. 

Located on the southeastern fringe of Europe, Greece for decades has been on of the main entry points into the EU for people fleeing conflict and poverty in the Middle East, Africa and Asia. 

Tens of thousands make it into the country each year, the vast majority on dangerous sea journeys either from the Turkish coast to nearby Greek islands in the Aegean, or making the much longer Mediterranean crossing from North Africa to the southern Greek islands of Gavdos and Crete.

Athens has taken an increasingly hard line in dealing with migration. 

Earlier this year, Greece began working with four other European countries to set up deportation centres in third countries, most likely in Africa, for migrants whose asylum applications are rejected.

Greece's migration minister Thanos Plevris said the government was working with Germany, the Netherlands, Austria and Denmark for the creation of so-called return hubs, 'preferably in Africa.' 

Ministers from the five countries had already met to discuss the issue, and technical teams would be meeting next week, he said.

'We are not speaking theoretically any more, we are speaking practically,' Plevris said. 

He didn't specify which countries were being considered to host the return hubs, and said the choice of the African continent was 'not binding.' 

It was the larger European countries that were speaking directly with the countries where the return hubs could be located, 'but we are participating too,' he added.

The use of return hubs would be for people whose asylum applications are rejected and whose countries of origin will not take them back, the minister explained. 

He said their existence would act as a deterrent to prospective migrants who are unlikely to be granted asylum. 

The minister said the aim was for an initial plan to be in place in the next few months, although it wasn't clear when any such return centres could be up and running.