The chief of the European Union's border patrol agency FRONTEX was to be face the bloc's lawmakers over whether refugees and migrants had been pushed back out of Greece, sent back to sea while trying to reach islands or cross land borders.

Human rights groups and activists disputed claims by FRONTEX Executive Director Fabrice Leggeri that there was no evidence the agency or Greece's Coast Guard had engaged in pushbacks although they've said little about Turkey continuing to send refugees and migrants in violation of an essentially-suspended 2016 swap deal with the EU.

Other EU countries closed their borders to refugees and migrants or reneged o promises to help take some of the overload, leaving Greece to largely deal with detaining some 100,000 in camps and centers, including 34,000 on five islands near the coast of Turkey, which isn't being censured.

A joint investigation published in October by media outlets Bellingcat, Lighthouse Reports, Der Spiegel, ARD and TV Asahi said that video and other publicly available data suggest FRONTEX “assets were actively involved in one pushback incident at the Greek-Turkish maritime border in the Aegean Sea.”

The report said personnel from the agency, which monitors and polices migrant movements around Europe’s borders, were present at another incident and “have been in the vicinity of four more since March.”

FRONTEX did its own investigation and Leggeri said in October that “so far, no documents or other materials have been found to substantiate any accusations of violations of the law or the FRONTEX Code of Conduct by deployed officers.”

He said the agency does “not tolerate any violations of the fundamental rights in any of our activities,” and Greece's New Democracy government also denied the Coast Guard or any other officials pushed back refugees and migrants.

Pushbacks are considered contrary to international refugee protection agreements, which say people should not be expelled or returned a country where their life and safety might be in danger due to their race, religion, nationality or being members of a social or political group.

The EU though also has the so-called Dublin Regulation which stipulates people can seek asylum only in the first country in which they land, mostly Greece as they had gone to Turkey first fleeing war and strife and economic hardships in their countries in the Mideast and sub-Saharan Africa.

Turkey has let human traffickers keep sending them to Greece, mostly to islands, although in lesser numbers during the COVID-19 pandemic and they can't land in places like Germany first, locking Greece into taking them, almost all seeing sanctuary.

FRONTEX's board met to discuss the repeated allegations although the issue hasn't been taken up by the EU's commissioner dealing with refugees and migrants, Margaritis Schinas from Greece's ruling New Democracy, the agency's board later saying the European Commission now wants a further probe.

The allegations came as the EU unveiled sweeping new reforms to its asylum system which critics said were too weak and came more than five years after more than one million people, mainly Syrian refugees, used Turkey to get to overwhelmed Greek islands.

Part of the EU's migration reforms includes a system of independent monitoring involving rights experts to ensure that there are no pushbacks at Europe’s borders, especially Greece.

FRONTEX said its work in the eastern Aegean Sea has been complicated by a dispute between Turkey and Greece over their maritime borders. Greek and Turkish coast guard ships are routinely involved in standoffs and threats in the relatively narrow stretch of water that separates the two countries. 

(Material from the Associated Press was used in this report)