Mohammed Abu Mustafa spends most of his days sitting in his small coffee shop on the edge of Akçakale, a Turkish border town that straddles the Syrian border.

The coffee shop is barren most days, except for a few friends who gather to share a water pipe while playing dominoes. However, Abu Mustafa is unfazed by the lack of income from the shop.

"That's the real business," he tells the Sunday Herald, nodding his head across the street toward a chain-link fence 50 metres away - manned by just a few patrolling Turkish soldiers. On the other side sits Tal Abyad, a small Syrian city, now an Islamic State (IS) stronghold.

The city, about 20 miles east of Kobani, has been under IS control for a year, having been previously taken from the Free Syrian Army (FSA). Now it forms an integral part of IS's self-proclaimed caliphate, where residents live under draconian laws, including fingers being cut off as punishment if a person is caught smoking, and women being lashed if they are not fully covered.

Abu Mustafa has been smuggling goods back and forth across the border for years, but his main focus has changed since the outbreak of war in Syria.

"Everybody comes here illegally. It's become good business; we used to take cigarettes across the border, now it's people," he says. "I have a big group of smugglers who work under my direction, on both sides. We can take people in and out easily."

Abu Mustafa, a slim man in his thirties, is today sporting an impeccably ironed suit jacket and shiny leather shoes - both of which look slightly out of place in the dingy coffee shop. He plays with a small string of prayer beads in one hand, constantly wrapping the string through his fingers while he leans back in his chair, taking puffs from an old tobacco water pipe with an air of confidence.

He not only supports IS, but has become an integral part of their organisation.

"I am part of the Islamic State," he proudly states, as other men gathered around him - all are affiliated with the jihadist organisation; many of them also work under his direction in the smuggling business.

"If you want to go in, we can help you," one of his associates says. "If you go inside right now, only you know yourself if you will die or not - but if you are against them [Islamic State] of course you will die."

He is just one of many who make the trip in and out of neighbouring Islamic State territory from Akçakale. Young men with long beards, sporting the now infamous checkered scarf, can now be spotted in almost every crowd milling down the town's streets.

"I go there a lot, and I know exactly where I am sending every single person, I know every person and everything there," Abu Mustafa says proudly, before turning to bark orders at a young man behind him.

"I knew the people in charge on the other side before they joined the IS. Now we all work together. I know everybody on the other side, I know who is with us, IS and who is not. And you have to be with us."

According to Abu Mustafa, the people he smuggles over the border are mostly would-be IS recruits - "90% of the foreigners that come here I smuggle through to join the IS, they're from all over the world - America, Europe, everywhere".

While the process is secretive, Abu Mustafa says he isn't a hard man to find. Residents connected to the underbelly of the town know his business, and easily recommend his skills. But he insists not everyone can be smuggled in - business for him is half making money, half supporting IS.

"I need to know why you are going there, for what reason, and then I tell them [the Islamic State commanders]. When I call them to help send you there, they ask, 'Who is this, why is he coming, for what reason?'. They need to be convinced, and I need to be convinced. These people [Islamic State] are my family."

If the potential recruit checks out with IS and Abu Mustafa decides he trusts the client, they then agree on a price. To hire his services, he says, costs around $150 to go from Turkey into Islamic State-controlled Syria, while the trip back is a heftier fee ranging between $300 to $400.

"The [IS] government doesn't pay to get you inside," he clarifies. "You have to pay yourself to get inside, pay me - and then you can join them. But you have to contact a commander, often online, first, and they put you in contact with us to get you in.

"And we don't just leave you on the street on the other side either, we take you to a recruitment house, and then to where you have been told to go - if someone was smuggled in, had made no contact, and was just left on the street, they would be killed.

"When you get in, the guys on the other side who I hand you to will take you away for one month's training. This training is so they get to know you - they will not give you a gun on the first day you go inside. After one month, if they trust you, once you have convinced them you are with them, then you will fight. If after this month they don't trust you, you will be killed."

He adds: "If you want to go in, then easy, but only God knows if you will stay safe or not."

Additional reporting by Abed al-Qaisi