Islamic State is exploiting the Mediterranean refugee crisis to smuggle fighters into Europe, an investigation has found.
The extremist group is working with human trafficking gangs to transport its members into the West by hiding them among refugees on boats, intelligence analysts said.
Sources claim IS is also capitalising on the emergency in the region to fund its terrorist activities by taxing people smugglers.
Abdul Basit Haroun, an adviser to the intelligence service of the Libyan government, said he had spoken to boat owners who operate in IS-controlled areas who told him the group takes a 50% cut of their income. The proceeds can run to tens of thousands of pounds per vessel.
He told BBC 5 live Investigates: "The IS, what they are doing they are not controlling the boat. They give permission for the boat owner to use the spot under their control and they charge them for that 50/50 of whatever they make.
"They use the boats for their people who they want to send to Europe as the European police don't know who is from IS and who is a normal refugee or not.
"The boat owners have a list of who to take but some people come suddenly out of the list and they're told take them with you.
"They sit down separately, they come alone and in the boat they are not scared at all. They are for IS - 100%."
Asked why IS would be doing this, he said: "I think they do something for planning in future, not for today or tomorrow."
The investigation also uncovered separate claims that two Egyptian brothers travelled from the Libyan city of Sirte to Europe in March after they were told by human traffickers that IS offered easier, safer and cheaper journeys to the West.
They revealed how IS offers people wishing to migrate the chance to stay and fight in Libya.
If they insist on leaving for Europe, all migrants are given one week of religious education, which they are told is to safeguard them against Europe's temptations.
Earlier this year, European border agency Frontex warned it is possible that foreign fighters are using "irregular migration routes".
Frontex warned in its annual risk analysis that with record numbers of migrants crossing the border illegally, resources are devoted to their immediate care "rather than screening and obtaining information on their basic characteristics such as nationality".
It said: "A fter they are rescued, they continue their journey to other member s tates and not knowing who is travelling within the EU is a vulnerability for EU internal security."
Another report published earlier this week raised concerns about the involvement of IS in the human trafficking trade.
The analysis, produced by the Global Initiative against Transnational Organised Crime, said the lucrative coastal migrant trade in Libya "dwarfs any existing trafficking and smuggling businesses in the region, and has particularly strengthened groups with a terrorist agenda, including the Islamic State".
This week Scotland Yard revealed that more than 700 British extremists are now known to have travelled to Syria, with a "significant proportion" making the journey to join IS.
:: BBC Radio 5 live Investigates is on today at 11.00 am.