The European Union's top prosecutor says she has been told that Islamic State terrorists are being smuggled across the Mediterranean hidden among migrants.

Michele Coninsx, head of the EU's judicial co-operation agency Eurojust, has confirmed she received the intelligence as part of the organisation's efforts to respond to illegal immigration, terrorism and cybercrime.

Ms Coninsx said Eurojust's co-ordination efforts are ongoing and she could not divulge what EU nations have told the agency.

Migrants sit on the landing craft of HMS Bulwark after being rescued from the Mediterranean. The EU's top prosecutor has said ISIS terrorist are hidden among them

But she said groups such as ISIS are also using proceeds from people-trafficking to fund terrorism.

Ms Coninsx, a career prosecutor from Belgium said: 'We're going after the criminals. We're going after the money.

'It is an alarming situation because we see obviously that these smugglings are meant to sometimes finance terrorism and that these smugglings are used sometimes to have and ensure infiltrations by members of the Islamic State.

Paying large sums of money for a shot at reaching Europe, tens of thousands of people have left Libya in unseaworthy and overcrowded boats or dinghies over the past two years. An unknown number have drowned.

This year, about 70,000 migrants have been rescued, many by an EU-led naval operation.

Ms Coninsx said an Italian official told Eurojust three weeks ago the flow of migrants has risen fivefold.

Paying large sums of money for a shot at reaching Europe, tens of thousands of people have left Libya in unseaworthy and overcrowded boats or dinghies over the past two years

Michele Coninsx, head of the EU's judicial co-operation agency Eurojust, pictured left, has confirmed she received the intelligence as part of the organisation's efforts to respond to illegal immigration, terrorism and cybercrime

Often the smugglers mingle with the migrants in the hope they will not be caught - although dozens have been arrested in Sicily and other parts of southern Italy.

Meanwhile Britain has been warned to brace itself for 'boats full of terrorists' if Islamist fanatics are allowed to cement their foothold in Libya.

Egypt's Ambassador to the UK said the flood of migrants from north Africa poses a new threat now that the Islamic State controls the Libyan coastal town of Sirte.

It comes after officials have previously spoken of their fears that militias loyal to ISIS could bring Somalia-style piracy to the Mediterranean.

Fighters that have sworn allegiance to the Islamic State have made sweeping new inroads in Libya, and have taken numerous coastal towns, just a few hundred miles across the water from mainland Europe.