GETTY/IG ISIS are using the migrant crisis to infiltrate Europe, Brussels has admitted

Officials at Frontex admitted a string of security blunders which have led to a large number of people arriving in Greece and Italy with false documents not facing thorough checks or penalties. It said the Paris attacks last November demonstrate how the chaos caused by the ongoing migrant crisis could be used by terrorists to reach the EU, with the aim of slaughtering innocent civilians.

Brexit campaigners tonight said the startling admission proves that Britain's security is being directly compromised by our links with Brussels. Britons will vote on whether to maintain our relationship with Brussels in a landmark referendum on June 23.

GETTY The EU's border agency Frontex admits insufficient checks are being carried out

IG ISIS has boasted of sending fighters to Europe posing as refugees

The bombshell report, Risk Analysis for 2016, concluded: "The Paris attacks in November 2015 clearly demonstrated that irregular migratory flows could be used by terrorists to enter the EU. "Two of the terrorists involved in the attacks had previously irregularly entered through Leros and had been registered by the Greek authorities. They presented fraudulent Syrian documents to speed up their registration process. "As the vast majority of migrants arrive undocumented, screening activities are essential to properly verify their declaration of nationality. "With a large number of persons arriving with false or no identification documents or raising concerns over the validity of their claimed nationality - with no thorough check or penalties in place for those making such false declarations, there is a risk that some persons representing a security threat to the EU may be taking advantage of this situation."

GETTY There were more than 1.8 million illegal border crossings last year

GETTY Brexit campaigners said the report shows the EU is endangering Britain

Islamist extremists will exploit irregular migration flows whenever such movements' fit their plans Frontex report

Investigators also raised concerns that EU citizens who had joined Islamic State in Syria were taking advantage of the irregular migrations flows to return home. They added: "The staggering number of EU citizens who joined the conflict as jihadists has resulted in a number of returnees opting to use irregular means of travelling. "Islamist extremists will exploit irregular migration flows whenever such movements' fit their plans." The shock admission came as it emerged that more than 1.8 million illegal border crossings were detected by EU member states in 2015, a whopping six times the number reported in 2014.

In the latest sign that Brussels is increasingly waking up to the madness of its immigration policies, EU officials today concluded that "the unprecedented number of detections of illegal border-crossing has also led to a surge in violent incidents along the EU's external borders". They added: "People smugglers, motivated by profit, increasingly put migrants' lives at risk and even threaten border guards to recover boats or escape apprehension." The report was seized on by campaigners wanting to leave the EU, who said the UK was at risk from terrorists able to slip through European borders. Discussing the findings, UKIP defence spokesman Mike Hookem said: "[The report] was yet more proof that we are safer off outside the European Union. "Those who immediately pointed out that the EUs open borders were a security threat faced abuse from all sides in a knee jerk reaction by detractors despite the causes of this hideous attack being quite obvious from the outset. "It stands to reason that with no checks or penalties in place for those making false declarations there will be an increase in numbers of people who wish us harm making use of the migrant crisis to get into the EU and crossing its internal borders freely. "It also means that home grown Jihadis who have been allowed to live in extremist ghettos can move around without attracting suspicion and spread their message of hate and pass on the skills they have learnt from travelling overseas to places like Syria to cause their carnage."