The German weekly Der Spiegel published footage on Thursday showing masked Greek law enforcement officers forcibly sending back refugees to areas near Turkey.

Six retired and serving Greek police officers and soldiers confirmed to reporters that they have been conducting "pushbacks" at the Greek-Turkish border through the Evros river for years, according to Der Spiegel.

The footage that consisted of 11 videos in total, was taken by security cameras on the Turkish side of the Evros and showed migrants being forcefully taken across the river by masked men in military camouflage clothes and boots. Reportedly, it was not possible to identify the masked officials; yet, there were indications that these men were working for Greek authorities or were acting on their instructions since the area of the footage is a militarized zone that can only be entered by few people.

The footage showed people being taken to the Turkish side in groups with small inflatable motorboats and left there. Yet, how the masked men were crossing the border of the two countries could not be recorded. It was also determined that the illegally pushed-back refugees were speaking several different languages. It has been speculated that these were irregular migrants seeking asylum in Europe, as it was the case for many refugees that have been trying to cross the Mediterranean in recent years.

The collective Forensic Architecture of Goldsmith University, a London-based research group, has analyzed the 11 videos for Der Spiegel and determined that the video was recorded on Sept.17, 2019 at around 10:30 a.m. and 12:30 p.m., although the footage falsely showed the date to be 2018.

"Spiegel posted yesterday a revealing video of the deportation of migrants to Evros. Independent and serious research needs to be done on this subject and finally, there is audiovisual material," Eva Cossé of the Human Rights Watch tweeted Friday in Greek.

Under international laws and conventions, Greece is obligated to register any illegal migrants entering its territory; yet, this is not the case for thousands of migrants who were forcibly returned to Turkey, especially since the beginning of the refugee influx into Europe in 2015.

In the first 10 months of 2019, 25,404 irregular migrants were pushed back into Turkey by Greece, the Foreign Ministry announced at the end of October, a significant increase from the 11,867 migrants pushed back in 2018. The ministry has frequently voiced that pushback practices were contrary to international law and called on the Council of Europe to suspend and investigate Greece’s practices.

Turkey and the European Union signed a deal in 2016 to curb illegal immigration through the dangerous Aegean Sea route from Turkey to Greece. Under the deal, Greece sends back migrants held in the Aegean islands that crossed from nearby Turkish shores and in return, EU countries receive a number of Syrian migrants legally. The deal, reinforced with an escalated crackdown on human smugglers and more patrols in the Aegean, significantly decreased the number of illegal crossings.

However, some desperate migrants still take the route across the better-policed land border between Turkey, Greece and Bulgaria.