And in a joint report unveiled today, the two police agencies said those preying on desperate refugees had raked in up to USD 6 billion (5.2 billion euros) last year. That had turned the migrant flow into one of the largest money-earners for organised crime on the continent.
"Terrorists may use migrant smugglers' resources to achieve their goals," said the report by the global police body Interpol based in Lyon and Europol in The Hague.
Although no regular links between criminal gangs and terror groups have been proven "some incidents have been identified involving terrorists who have made use of migratory flows to enter the EU."
It pointed to the November 13 attacks in Paris, after which it was revealed that two of the attackers had entered Europe through Greece as part of an influx of refugees from Syria.
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"More than 90 percent of all migrants reaching the European Union use the facilitation services of a migrant smuggling network at some point throughout their journey," said Europol director Rob Wainwright.
"This is a clear indication that organised crime networks are profiting from mass migration."
The report calculated that each migrant had "paid an average of USD 3,200 to 6,500 (EUR 3,000- 6,000)".
"This would result in an average turnover of USD 5 to 6 billion in 2015."
"In Libya alone, around 800,000 migrants are waiting to travel to the EU," it said.