A European Union commissioner said Thursday that the bloc's border agency harmed its reputation by taking too much time to investigate alleged migrant pushbacks from Greek territorial waters toward Turkey in the Aegean Sea.

EU Commissioner for Home Affairs Ylva Johansson was speaking at the hearing of the European Parliament's special scrutiny group, dedicated to investigating the European Border and Coast Guard Agency's (Frontex) alleged participation in pushing back asylum-seekers and migrants.

"Investigation is important for the trust and reputation of the agency so that it (the allegations on pushback) could be clarified as soon as possible," Johansson said as quoted by the Anadolu Agency (AA).

"It has taken too long, and it hasn't been good for the reputation of the agency," the EU commissioner pointed out, referring to the fact that complicity in pushbacks was reported in October, and the EU agency only concluded a preliminary report by March.

"You should be prepared to deal with reports on incidents, misconduct or alleged pushbacks," Johansson added.

In recent years, Turkey and Greece have been key transit points for migrants aiming to cross into Europe, fleeing war and persecution to start new lives. Turkey has accused Greece of large-scale pushbacks and summary deportations without access to asylum procedures, which is a violation of international law. It has also accused the EU of turning a blind eye to what it says is a blatant abuse of human rights.

Pushbacks are considered contrary to international refugee protection agreements that say people shouldn't be expelled or returned to a country where their life and safety might be in danger due to their race, religion, nationality or membership in a social or political group. Such actions prevent asylum-seekers from making claims for refugee status and if practiced indiscriminately against a group of migrants it can constitute refoulement – a violation of EU human rights laws and the 1951 Geneva Convention.

The head of the EU border agency, who also participated in the European Parliament's hearing, said that their internal investigation had not found any evidence on pushbacks.

"There was no substantiated, evidence-based facts or conclusions which say that Frontex would have participated in pushbacks or would have carried out violations of fundamental rights," Fabrice Leggeri insisted.

Earlier this year, the managing board of the Frontex said that it did not find evidence of rights violations in cases it reviewed where guards were accused of illegal migrant pushbacks from Greece toward Turkish territorial waters. But the body added that its conclusions only applied to some of the disputed incidents, saying it needs additional clarifications to complete the remaining reviews.

Leggeri has been under pressure for weeks over the allegations as Frontex takes on a greater front-line role in patrolling EU borders. EU lawmakers and activists have called for him to resign over the operations, but he has refused to, insisting the agency is key to the fight against human trafficking.

A working group of 14 members of the European Parliament was formed last week to investigate the EU border agency's involvement in pushbacks of asylum-seekers in Aegean waters.

A joint investigation by several international news outlets reported in October that Frontex had been complicit in maritime pushback operations to drive away migrants attempting to enter the EU via Greek waters. A month later, Brussels-based news outlet EUobserver revealed that Frontex exchanged letters with Greek authorities on Athens' orders to push back migrants to Turkish waters.

The pressure intensified after media and rights organizations documented multiple cases of Frontex border officers, alongside national counterparts in EU countries, forcing migrants back, particularly along Greece's sea border with Turkey. At least six incidents in which Frontex units were involved in pushbacks near the islands of Lesbos and Samos between April 28 and Aug. 19 have been documented.

While the border agency is required to rescue migrants, the Frontex vessels patrolling the area sped past the overcrowded, inflatable boats, creating dangerous waves to force them to return to Turkish shores. A Frontex aircraft was also documented passing over migrants, who were seeking help at sea, but did not rescue them.

The Berlin-based rights group Mare Liberum also said in January it had documented 321 incidents from March to December 2020 involving more than 9,000 people. Mare Liberum's report said that in addition to the Greek coast guard, Frontex and ships under NATO command were also involved in "systematic and illegal expulsions."

In a statement issued last week, Turkey urged Athens and "all elements involved in pushbacks" to end their violations of international law, human rights agreements and a migration deal between the EU and Turkey.

The Turkish Foreign Ministry's statement cited two incidents on Feb. 23 and Feb. 24 in which Greek forces assaulted groups of asylum-seekers, took their valuables and left them stranded on an island in the middle of the Maritsa (Meriç) River.

Over 80,000 asylum-seekers have been pushed back to Turkey in the last four years, the ministry said, accusing Greece of pursuing a "systematic policy" for years on pushbacks with the involvement of Frontex.