Four non-governmental organizations (NGOs) working on the island of Lesbos reportedly worked with Turkish human traffickers sending refugees and migrants to the island and even spied on Greece' Coast Guard.

That was based on an investigation from Greece's EYP intelligence service, said Kathimerini, as part of a broader probe into whether some of the volunteer groups were colluding with Turkey or committing other wrongdoing.

Lesbos, along with four other islands near Turkey's coast, are holding some 34,000 refugees and migrants who came from Turkey, where they had gone fleeing war, strife and economic misery in their homelands, especially Iraq and Afghanistan and sub-Saharan Africa.

Turkey, under an essentially-suspended 2016 swap deal with the European Union, is supposed to hold more than 4 million refugees in return for 6 billion euros ($7.06 billion) in aid, faster-track entry into the bloc and visa-free travel for its citizens.

Greek authorities relied on two foreign nationals sent to western Turkey to pose as would-be refugees, approaching human smugglers that Turkey lets operate in violation of the agreement.

The Kathimerini report cited classified information identifying 35 members of four NGOs as coordinating the travel and landing of illegal migrants and would-be asylum seekers on the Greek isles, especially Lesbos, via “illegal methods and procedures.”

The suspects are identified as citizens of Germany, France, Switzerland, Austria, Norway and Bulgaria, with two of the groups based in Berlin but no one was identified in keeping with Greek privacy laws that expose the names of politicians and others on a regular basis.

The clandestine operation was code-named Alcmene, named after the mother of the mythological hero and demigod Hercules, and carried out in mid-August, the newspaper also said.

One of the favored tools of the accused, the report added, is  theAlarmPhone app, an emergency communication channel said used by migrants when in distress while crossing the Mediterranean or Aegean.

Critics said distress calls, by the refugees or migrants or the NGOs, are being wrongly used to get the Greek Coast Guard to pick people up in boats in waters where scores have drowned trying to reach Greek islands since the crisis began in 2015.

Greek media reports said if the emergency calls are ignored or action delayed, then AlarmPhone cadres and NGO staffers take to social media to demand action and apply pressure on the government.