Fresh concerns have been raised about Europe’s ability to protect its borders after a Sunday Telegraph investigation found that asylum seekers are managing to enter the Schengen zone undetected, and fly on fake ID cards. Syrian, Iraqi and other nationals are walking across Turkey’s land border with Greece, where they are buying fraudulent documents that have been accepted on commercial flights to western Europe. By doing so they are getting around a deal the European Union (EU) agreed with Turkey, that said Turkey would take back illegal refugees arriving on Greek shores from the country.

The Sunday Telegraph spoke to three Syrians who made it to the Netherlands this way this year, as well as an Iraqi citizen who reached Belgium. Europol, the European Union’s law enforcement agency, last night admitted the problem was much wider. The shocking ease with which the asylum seekers made the journey raises serious questions about the EU’s ability to protect its external perimeter, particularly at a time when Daesh is looking for ways to send fighters to attack European cities. One Syrian man in his 30s, who wished to use only his first name, Ahmad, spoke of how he paid €1,000 (Dh4,196) to a smuggler in Istanbul to help him reach Greece. “If you have the money, there is a luxury way,” Ahmad said. “We travelled by car from Istanbul to Edirne [in north-west Turkey], then we walked for an hour to the river [Meric], and from there we got a boat which just took two minutes.”

He crossed illegally into Greece, negotiating his way around guards at one of the world’s busiest border gates with the help of the smuggler. He took a taxi and then a coach to Athens. Once in Athens, Ahmad paid another smuggler €6,000 for a fake Greek ID card. The card bore his photograph but the name of a real Greek citizen. With it he managed to buy a plane ticket to Amsterdam. Under the Schengen Agreement, people are able to travel around EU member states without showing a passport. During the height of the refugee crisis, in the summer of 2015, Greek authorities reported finding up to 200 forged passports and IDs a day at Athens airport. But the trade was thought to have tailed off after the EU and Turkey signed a deal under which Ankara stopped asylum seekers from crossing by sea to the Greek islands in return for euros 3 billion in aid.

The agreement all but halted the perilous journeys made across the Mediterranean from Turkish ports, but alternate routes have since opened up for those able to afford it. The land border crossing into Greece is an expensive option as the risk is high, and smugglers can charge several thousand euros for a fraudulent document. Ahmad claimed few checks were carried out at the airport in Athens and he was able to board the plane with little questioning. “Nobody asked me anything at the airport,” he said. “Then when I got to Amsterdam I spoke in English and was waved through. I was so scared they would catch me, but they didn’t. “I started the day in Istanbul, I finished it in Athens. It wasn’t difficult.” He said refugees choose destination countries they believe have lax security. “We heard some countries are harder to get to than others,” he told the Sunday Telegraph by phone. “The UK is very difficult as it’s not in Schengen, and Germany is also tricky because there are lots of German police searching planes leaving from Greece. But it is possible to sneak into others.”

He said he was travelling with a group of 10 people and knows of at least one other who made it to western Europe. A few days after arriving in the Netherlands, where his brother has been living for several years, Ahmad declared himself to immigration authorities and sought asylum. Under the Dublin Regulation, asylum seekers should be sent back to the first Schengen zone country they reached — in this case Greece — but Ahmad was allowed to stay. Ahmad is a Syrian Kurd who fled to neighbouring Iraq four years ago to avoid being forcibly recruited into President Bashar Al Assad’s army. He was last week granted a five-year residency permit. “I still don’t believe I’m in Amsterdam,” he said from his new home in the Dutch capital. An Iraqi national followed the same route in March this year, also using a fake Greek ID bought from a smuggler in Athens. He attempted the trip twice before he was successful. “I guess because I look sort of European, they just assumed I was,” he said from Brussels. Concern about Europe’s border-free zone has grown ever since the terrorist attacks in France and Belgium, which revealed how known extremists were able to cross borders with few or no checks.

At least three of the Paris bombers travelled from Syria to Europe via Turkey on false passports supplied by Daesh handlers. As the terror group’s so-called caliphate crumbles many foreign fighters are looking for ways to return home, where it is feared they will carry out attacks. Dozens have fled Syria in recent months, most of whom have been caught by Turkish border guards but some are thought to have evaded capture.

A spokesman for Europol said the journey the refugees described “doesn’t shock them”. “There are fewer migrants who travel by plane than by train or car, but in terms of freedom of movement it doesn’t really change that much,” he said. “Travelling by plane is of course more expensive and the risk of being caught is still higher. Not all, but some airlines do ID checks before boarding the plane, some EU member states have reinstated temporary border checks and border police can do ad hoc checks on anyone.” There is no EU-wide system of document inspection, while increasingly sophisticated physical and security features of travel documents present significant challenges for border officers. She said that ID and document fraud had become one of the agency’s “top priorities” when it came to migrant smuggling. A spokesman for Frontex, the EU’s external border agency, told the Sunday Telegraph that they detected more than 7,000 people with fake documents at the EU’s external borders last year. He said they had reported an increase in the number of cases of document fraud in recent months, and were offering help to Greek and Italian authorities to help detect the counterfeits.