The proportion of migrants using covert means to enter Europe is expected to rise sharply this year despite European nations pouring at least 17 billions euros ($19 billion) into reducing migration over the past 18 months, researchers said on Friday.
The Overseas Development Institute (ODI) said about 60 per cent of migrants arriving in Europe this year are expected to use covert means, such as false passports, hiding in trucks or overstaying their visas, compared with 35 per cent in 2015.
In a report ahead of next week's UN Summit for Refugees and Migrants, the UK-based thinktank said 330,000 people are projected to arrive in Europe this year by sea, usually across the Mediterranean, compared with 1.1 million in 2015.
But ODI said this figure may create a false impression for European policy-makers that the migration crisis is over, as it fails to take account of other migrants entering covertly.
"While on the surface, the number of people arriving in Europe has fallen, the rate of those taking hidden routes to Europe has not been affected and is likely to increase," said Marta Foresti, author of the report in a statement.
"These covert routes can be more dangerous and make it harder for governments to monitor migration and design effective responses."
Since 2014 European countries have committed to spending 1.7 billion euros on tighter border controls, including a British plan to build a wall along the approach road to the French port of Calais to prevent migrants from jumping onto UK-bound trucks.
More than 15 billion euros has been spent on bilateral agreements, such as the EU-Turkey deal aimed at reducing the number of migrants travelling from Turkey to Europe.
