GETTY Turkish MPs have accused the government of turning a blind eye to the movements of jihadis

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The leaked call data, seen by Russia's state-backed broadcaster, reportedly shows how local rebel groups are helping ISIS fighters to sneak into Europe for complex surgical procedures. If true it raises fresh concerns over the EU's agreement to give Turkey visa-free travel, as jihadis could potentially move freely into the bloc's 28 member states. Turkish opposition MPs have accused the government of turning a blind eye to the illicit movements of jihadi fighters.

Ankara has vehemently denied any suggestion it has offered a safe haven to injured ISIS fanatics and their families. But Turkish security services are alleged to have intercepted the communications without acting on them. The latest audio files, which have not been independently verified, appear to suggest at least some of those injured on the battlefield are being treated in Turkey.

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Expensive medical treatment, accommodation and meals are all paid for by ISIS, according to RT. In the tapped phone calls, a leading figure in the militant group, Ilhami Bali, is apparently heard speaking to a man, known only as Savas, who is in charge of arranging medical services at a Turkish hospital. Asked by Bali if the "sick people" arrived at the unnamed hospital in southern Turkey, Savas says: "Yes they came. They were operated."

GETTY There are fresh concerns over the EU’s agreement to give Turkey visa-free travel

GETTY A huge concrete wall on the Turkish Syrian border has not stopped ISIS getting in

The pair then discuss medical treatment totalling almost £30,000, which included fitting a prosthetic leg, a likely result of a bombing or mine explosion. Bali says: "He's been here for two to three months because he does not want to amputate his leg. "We made a lot of business together. We sat and ate together. So there is no problem, brother. We made an agreement on $40,000." Savas later adds: "I have made a list of everything after we have talked about it. How they made it what they did, etc. I don't want a package thing but there are three persons who get medical operation."