The diminutive figures were lined up outside Catania’s central station. There were seven in all, aged between 15 and 17. They had recently escaped from the massive government-run migrant reception centres inland or further along the Sicilian coast. Now they were alone, waiting for the city’s matrix of organised criminals to take them north.

“We have nowhere to go, we feel safer outside on our own than in the camps,” said Mohammed Asante, 17, from Ghana. Thousands of unaccompanied minors have disappeared from Catania, mostly through smuggling networks.

It is a lucrative trade, so it should come as no surprise that Cosa Nostra, the Sicilian mafia, may be exploiting this latest market in human suffering.

Anti-mafia prosecutors have revealed to the Observer that they are currently investigating the Italian government’s network of official homes for unaccompanied minors, believing that child refugees are being targeted in the very places they should be protected. They also claim to have uncovered widespread corruption, involving alleged kickbacks and bribes to secure lucrative public contracts to run migrant camps.

According to prosecutors, there is also a British connection to the smuggling rings that are targeting migrants. Money has been wired directly to criminals based in London from refugees inside Italian reception centres.

This week the House of Lords will publish a parliamentary report into Europe’s treatment of unaccompanied minors. As the surge of refugees from the most troubled regions of the world shows no sign of letting up, concern is mounting that children arriving in Sicily are being denied basic services. Money destined for them is, investigators claim, being taken to line the pockets of corrupt officials. Sexual exploitation is a genuine fear, say prosecutors, while teenagers from Africa and the Middle East are being forced to toil for little or no pay in harsh conditions in the fields around Catania.

The mafia’s involvement may also offer an explanation into one of the enduring mysteries of Europe’s migrant crisis: how have so many of its child refugees vanished without trace?

Most of the unaccompanied minors in Catania rarely seem to leave the patch of grass near the station, sitting quietly throughout the stupefying afternoon heat, occasionally washing in the fountain dedicated to the ancient Roman goddess Proserpina. “We are ‘bambinos’, but we had to leave the official camp because it was too full and there was too much fighting inside, we couldn’t defend ourselves,” said Ibrahim Jallow, 17, from Banjul in the Gambia.

As he spoke, Jallow glanced towards the smugglers staring back from along Via Don Luigi Sturzo. Abdelfetah, an Eritrean cultural mediator in Catania, estimates the smugglers have taken 1,000 children from Eritrea alone from the city over the past three years. He has no idea of their fate. “If they go missing, no one knows,” he said.

Latest figures suggest that more than 5,000 refugee children vanished without trace after arriving in Italy last year and registering with the authorities.

Speaking on condition of anonymity, an Eritrean police informant said Catania’s smuggling operations were organised by a mixture of Eritreans, Egyptians and Somalis. But everyone in Catania knows that Cosa Nostra retains overall control of the city’s underworld. “Nothing happens here without the mafia,” said Abdelfetah.

An indication of their grip on the city is the volume of Catanian businesses paying the pizzo – protection money averaging around £420 per month for an ordinary bar. Only 140 firms out of an estimated 10,000 in the city officially refuse to pay protection. “It’s a very severe problem, the mafia are everywhere,” said Salvo Fabio of Adiopizzo, a coalition of companies which defies the mafia by refusing to pay the tariff.

The Observer spoke to one migrant smuggler, a regular at the train station, as he returned home through the labyrinthine lanes of San Berillo, an inner-city mafia stronghold where runners peddle their drugs and the city’s Nigerian population control the city’s prostitution.

He refused to give his name. But when asked if Cosa Nostra was profiting from unaccompanied minors, he said: “Of course. We have an agreement, like the Nigerians and their women.”

As a youthful exodus from troubled African states continues, Catania is currently experiencing a surge in the arrival of child refugees. Overnight on 13 July, the Observer witnessed at least 20 new children, mainly from Asmara in Eritrea, arrive at the fountain. Some were as young as 12. As the heat drained from the city’s black streets, hewn out of lava from nearby Mount Etna, the stream of new arrivals kept coming.

Three Eritreans, aged 16, had escaped from an official migrant reception camp at Port Augusta and walked 25 miles up the coast. One shy Somali boy had fled a camp north of Catania. Hamsa, aged 12, was now sitting on his own, wondering what to do next.

The Eritrean informant who gave testimony to Operation Glauco, the Italian police initiative attempting to disrupt smuggling networks, said: “The numbers of children are increasing, their ages are getting younger, and at the same time the crime around them more organised. “We are seeing kids being taken out of the camps, or they get scared of living with adults and leave. Criminals involved in the smuggling are also believed to be becoming increasingly involved in other parts of the chain, they are working inside the reception centres.”

Some are working in places such as the government-funded Cara di Mineo camp. Twenty five miles inland from Catania, Cara di Mineo is an isolated former US army camp in a sweeping valley dotted with orange groves. Beyond its razor-wire perimeter, up to 4,000 migrants are crammed inside rows of terra-cotta houses. This is Europe’s largest migrant reception centre.

The anti-mafia team in Catania is investigating if the actual numbers of refugees inside the centre have been deliberately inflated to allow officials to pocket higher contributions from the government.

Firms looking after Italy’s wave of migrants receive £30 a day for each adult and £62 for a child. The total annual budget for Mineo is about £70m. “We suspect they try to spend a very small part on the migrant and the biggest part for them, this is the phenomenon,” said Andrea Bonomo, another member of Catania’s anti-mafia unit. The truth is that no one seems sure how many migrants are even inside the camp.

In theory children should not be in the camp at all, but the Observer has established that minors are being smuggled in illegally. Children held there describe intense overcrowding and cramped rooms holding five to six. Some live inside the remote facility for as long as 18 months, usually finding it a wretched experience. The centre has been plagued with allegations of prostitution, drug use and violence.

One unaccompanied 17-year-old, Diaby Aldemar, claimed to have spent a year inside Cara di Mineo before escaping due to violence and “bad” conditions. An Afghan teenager outside the camp called Abdul showed an identity card revealing he was 17. “I have spent two years in there already, waiting, but nothing has happened to my claim.” Many unaccompanied minors described smugglers taking them inside the centre and subsequently arranging for them to be taken north to countries such as Britain and Germany.

Many choose to escape. Most of the children outside Catania’s station had fled from Cara di Mineo, paying illegal minicabs parked at the camp £3.50 to take them to the city. Keita Saka, 17, from Bamako, Mali, spent eight months in the camp before fleeing, and said that smugglers approached him many times while he was there. “They ask where I want to go, England, Germany, Sweden. They said they can arrange from the inside.”

There is reason to suspect that Cara di Mineo has become in effect an open-air hub for smugglers, operating with the blessing of the mafia; a massive holding pen from where criminals take orders for human traffic.

Some of those orders come directly from the UK. Rocco Liguori, another anti-mafia prosecutor whose profession entails that he negotiates Catania’s streets in bulletproof vehicles, revealed they had been in contact with the British police and had uncovered proof that refugees stranded in Cara di Mineo were wiring money to individuals in Britain.

“We have evidence of smuggling towards the UK. We have collaborated with the British authorities. We have information about people receiving money in London from Cara di Mineo. The problem is about minors, thousands disappear. We used to think what are they doing with these minors? But in reality it seems many are just trying to reach their families in northern Europe,” he said.

Bonomo added: “We have evidence of minors paying money to escape, this includes to the UK. We are investigating if they are being exploited through labour and sexually.”

Those held in Cara di Mineo describe being deprived of vital services. Six senior officials connected to the camp have been told they are under investigation for their alleged roles in denying asylum seekers key services.

Akim Zakariyahu, 17, of Ivory Coast, says he spent months inside the camp: “They sometimes never gave us food and we hardly got any aqua [water],” he said. “Hardly enough to survive on. They use us only for business.”

Others allege that the authorities kept the children’s daily state allowance of £1.70 for weeks on end or withheld a proportion. “They keep the money, instead of 100% they keep 25%,” said his friend Diaby Aldemar, 16, from Mali.

Lucia Borghi works for the refugee charity Borderline Sicilia. She said that the treatment given to children arriving in Sicily was so poor that their health actually deteriorated after they reached supposed sanctuary following a treacherous Mediterranean crossing.

“They escaped terrible hardship, made horrendous journeys across the sea, and yet they look better when they arrive than they do after two years in Italy,” she said. The private company that runs Cara di Mineo has in the past denied all allegations regarding conditions at the centre, stating that law and order is strictly upheld and that the migrants are treated well.

The mafia’s exploitation of the migrant crisis extends far beyond Sicily. Investigations have linked the corruption in Cara di Mineo to Mafia Capitale, the recent scandal when crime syndicate involvement in the administration of Rome was exposed.

It is alleged that organised crime infiltrated public-service contracts on a grand scale, including those relating to migrant reception centres. One notorious underworld figure, Salvatore Buzzi, ran a vast cooperative that provided food and language courses for migrants and his combined business was said to be worth £30m.

In a wiretap recording, Buzzi, who has reportedly denied the allegations, is caught admitting: “Do you know how much we earn off migrants? Drugs are less profitable.”

Staring at the imposing mass of Mount Etna, Konate Akala from Nigeria could not stop shaking his head. The 17-year-old has been staying inside one of the official government camps for child refugees near the town of Giarre, 12 miles north of Catania, for three months and so far had watched 50 teenagers disappear. Another two had gone the night before. “A group of 15 Egyptian boys came about two months ago, first nine went, then another five. There’s just one left now.” The camp’s official capacity is 60 but it was holding 80.

“They always leave without saying anything, people must be telling them not to say a word. People arrange travel for you – they don’t come to the camp, they arrange to meet elsewhere. Most people want to go to Germany, Sweden, Britain,” said Akala.

Prosecutors in Catania have admitted that they are investigating a number of the camps over allegations that networks of smugglers are operating within them. Prosecutor Bonomo said: “They have a brother in Milan or Norway, Germany or Britain. The family wants the minor to reach relatives and so they pay. There are also investigations into exploitation of minors; there is a danger they are being exploited by criminal networks.”

The children at Giarre describe being sent on week-long projects, where they were told to move crops to waiting trucks. “They tell us it’s school but there are no lessons. At the end we get a certificate in Italian we cannot read,” said Akala. For those stranded in such camps, a frequent complaint is that nothing happens. Many claim that no lawyers visit, no immigration documents are received or asylum applications organised.

Joseph Mubundo, 17, from Conakry, Guinea, has been in Sicily for seven months but says his fingerprints have not even been taken by the authorities. He is tired of waiting. Soon, says Mubundo, he will follow the others and try his luck with the smugglers. “I might go to Catania, ask people. Why not leave? I am invisible already.”

As Sicily struggles to cope with the tide of desperate migrants and the dark forces of Cosa Nostra, Joseph and hundreds of others like him may well become the next “clients” to earn the mafia a tidy profit.

THE EGYPTIAN CONNECTION

An Egyptian people-smuggler has emerged as one of the key contact figures for Italian mafia groups seeking to extend their arms-dealing networks.

Fathi Abdelkader Mohamed Shalpy Garpua is believed to be the figure to whom the Sicilian mafia intended to sell firearms, in a transaction that shows Cosa Nostra is willing to work with criminal syndicates in north Africa. Intercepted phone conversations indicate that Garpua, from Port Said, was the intended recipient of assault rifles reactivated by the mafia in Sicily. Garpua is a central figure in a well-established criminal empire based in Alexandria, Egypt’s main smuggling centre. He is believed to be responsible for sending child refugees to Sicily and facilitating their journeys north to western Europe and probably the UK.

Catania’s anti-mafia prosecutors describe Garpua as a man connected to a “large” criminal organisation and no stranger to trafficking. Even before the Libyan and Syria wars, which sparked the migration crisis, Italian wiretaps outlined his role in an Italo-Egyptian immigration racket stretching from north Africa to Italy.

Police records show Garpua is also wanted for extortion. In May 2011 he is alleged to have kidnapped six child migrants from a refugee camp near Siracusa, south of Catania. Wiretaps reveal the abductions were intended as a message for families of migrants who had failed to pay for services provided by Cosa Nostra. MT

An Italian navy vessel arriving at the harbour in Catania with immigrants picked up from a boat in the Mediterranean. Photograph: REX/Shutterstock