After saying he could find no evidence that Greece or the European Union FRONTEX border agency he oversees were pushing refugees and migrants back toward Turkey, Fabrice Leggeri has found EU lawmakers demanding he quit.

Human rights groups, activists and a range of investigative media reports have claimed Greece's Coast Guard has pushed refugees and migrants in dinghies and rickety craft in the Aegean back toward Turkey or sent them back through land borders along the Evros River.

Greece's New Democracy denied it happened and Leggeri in October said there wasn't any proof but the row has intensified, including that FRONTEX, which helps patrol the borders including in the Aegean, helped to unlawfully stop migrants or refugees from entering Europe – which had closed its borders to them.

Members of the European Parliament called for Leggeri's resignation or firing and demanded in independent inquiry although there's been no call or reaction from the EU commissioner in charge of refugee and migrant affairs – Margaritis Schinas from New Democracy.

Leggeri was grilled over an investigation in October by media outlets Bellingcat, Lighthouse Reports, Der Spiegel, ARD and TV Asahi, which 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 launched an internal probe after the news broke.

“In his handling of these allegations, Executive Director Fabrice Leggeri has completely lost our trust and it is time for him to resign,” senior Socialist lawmaker Kati Piri said after the parliamentary civil liberties committee hearing. “There are still far too many unanswered questions on the involvement of Frontex in illegal practices,” she said.

Pushbacks are considered contrary to international refugee protection agreements, which 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 being members of a social or political group.

Turkey is holding some 4.4 million refugees and migrants who went there from other countries fleeing war and strife and economic hardship but let traffickers flood Greek islands since 2015, the numbers falling after a 2016 swap deal but hasn't faced any punitive measures.

FRONTEX's board met in October to discuss the allegation sand said the European Commission ordered another meeting, now set for Dec. 9.

“Migrants and refugees are very vulnerable to pushbacks by border guards,” Greens lawmaker Tineke Strik said. "We must be able to rely on an EU agency which prevents human rights violations from happening and not inflict them. But FRONTEX seems to be a partner in crime of those who deliberately violate those human rights.”

Leggeri said EU member countries have control over operations in their waters, not FRONTEX, and he called for the rules governing surveillance of Europe's external borders to be clarified.

“We have not found evidence that there were active, direct or indirect participation of FRONTEX staff or officers deployed by FRONTEX in pushbacks," he told the lawmakers. When it comes to operations, Leggeri said, “only the host member state authorities can decide what has to be done.”

He said his staff was under extreme pressure around the time of the alleged incidents in March and April because Turkish F-16 fighter jets had “surrounded” a Danish plane working for the agency and that its vessels were harassed by the Turkish Coast Guard and shots fired at personnel at land borders.

The allegations are extremely embarrassing for the European Commission. In September it unveiled sweeping new reforms to the EU’s asylum system, which proved dismally inadequate when more than a million migrants arrived in 2015, many of them Syrian refugees entering the Greek islands via Turkey.

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. Migrant entries have dropped to a relative trickle in recent years, although many migrants still languish on some Greek islands waiting for their asylum claims to be processed or to be sent back.

EU Home Affairs Commissioner Ylva Johansson told The Associated Press that she has confidence in FRONTEX's managing board but remains deeply concerned about the allegations.

During a visit to Morocco, Johansson said that the report "concerns me a lot. If it’s true, it’s totally unacceptable. A European agency has to comply to EU law and fundamental rights with no excuse.”

Johansson said she has “full confidence in the process that (has) gone on in the management board and the sub-group they are setting up” to continue the investigation, but, she noted, “There were a lot of questions put to the director. And he has not answered these questions.”

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