"My style is like Gaddafi - nobody can be more powerful than me," said Medhanie.

Smugglers extort thousands of pounds from migrants to escort them through the Sahara desert, onto boats waiting on the beaches of Libya, across the Mediterranean to Italy and from there to the affluent countries of northern Europe, including the UK.

Libyan smugglers are in collaboration with Eritreans, Ethiopians and west Africans – some of them former refugees who have made it to Europe and have been granted asylum, only to turn to the business of smuggling.

Asghedom Ghermay, an Eritrean, is accused of masterminding the smuggling operations from Catania in eastern Sicily, where many migrant boats end up.

He landed in Italy as a refugee himself two years ago and was granted asylum, with permission to live in the country until 2019.

He was arrested last week at Rome's Fiumicino airport as he was about to board a flight to Germany.

 

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He was wiretapped telling a collaborator that he was able to "send migrants to Germany for €500 [£360] a head, but it costs €1,100 to send them to Sweden, England or Holland."

The extent of the smuggling networks were revealed by prosecutors in Palermo, Sicily, who warned that according to their intelligence, up to a million migrants and refugees are languishing in makeshift camps and warehouses on the Libyan coast, waiting to cross to Italy.

"From the information we have, there are around a million people on the Libyan coast ready to leave," said Maurizio Scalia, a senior prosecutor.

He said that arrest warrants have been issued against 24 people, 14 of them in Italy but at least one of them at large in Libya.

Among them smugglers based in Libya is Ermias Ghermay, an Ethiopian, who was allegedly in constant contact with Asghedom Ghermay. They share the same surname but are not related.

He had already been named in an arrest warrant in connection with the capsizing of a boat in October 2013 off the coast of Lampedusa in which 366 people drowned.

Smugglers beat and torture migrants in order to extract more money from their families back home for the various stages of the odyssey to Europe.

Families who are anxious for the safety of their relatives are told to make payments to the smugglers through money transfer services such as Western Union and Postepay, or, for Arab migrants, through the informal "hawala" system in which relatives pay local brokers for each leg of the journey.

 

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It costs around $5,000 (£3,341) to be transported from West Africa or the Horn of Africa across the Sahara to the Libyan coast, investigators said in a 500-page document.

Migrants then pay around $1,500 for the boat crossing to Italy, and money on top of that to be put on trains and buses to Rome, Milan and across the Alps to northern Europe.

"From wiretaps we've ascertained that the average price for people coming from countries like Sudan, Eritrea and Libya is between $4,000 and $5,000.

Then, from Libya to Italy the journey costs between $1,000 and $1,500," said Mr Scalia, the prosecutor.

Smugglers showed no remorse or pity when, as happens all too often, the boats they despatched across the Mediterranean sank, either because of bad weather, engine failure or running out of fuel.

The Italians intercepted a telephone call last August in which one of the smugglers said that he believed that a boat carrying migrants had not made it to Italy. "I don't know what happened to them. Probably they're dead," he said.