It says SAR operations "help criminals achieve their objectives at minimum cost, strengthen their business model by increasing the chances of success."

It noted people on the boats in the start of last year made satellite phone calls to the Maritime Rescue Coordination Centre (MRCC) based in Rome.

Those rescues were then coordinated by EU's naval operation Sophia, Frontex, or Italian authorities. NGOs were involved in only 5 percent of the rescue incidents.

But the MRCC then saw a sharp drop in the calls in June, with NGO rescue operations increasing at the same time to more than 40 percent of all incidents.

"Since June 2016, a significant number of boats were intercepted or rescued by NGO vessels without any prior distress call and without official information as to the rescue location," says Frontex.

The Financial Times newspaper last December reported that Frontex, in a confidential document, suggested that NGOs were working with smugglers.

NGOs denied any collusion and noted that Sophia is destroying intercepted boats and therefore forcing more people onto even less seaworthy vessels.

Sophia has also saved over 32,000 but an estimated 4,500 people still died in the attempt last year alone, more than any other year.

Medecins Sans Frontieres (MSF), which also operates rescues near Libya, says it cannot be held responsible for the presence of smugglers.

"MSF did not create smugglers, just like MSF did not create the conflicts and deep inequality many of those we rescue flee," it said in December, following the FT report.

"The alternative implied by Frontex’s concerns about our rescue operations is to let people drown as a strategy to deter the smugglers," said MSF.

A spokeswoman at Frontex told this website last August that more people were being put on rubber boats than before.

She noted at the time that the average number of migrants on each 10-12 metre-long rubber dinghy also rose by more than a quarter. Some now have over 100 people onboard, rendering the vessels even more dangerous.

The €200 million Libya plan; humanitarian visas

The route has become the main entry point for people seeking a better life in the EU, which recently vowed to curb the flows ahead of the summer months and announceds a €200 million pan-north African fund largely geared towards Libya.

That plan includes boosting training efforts of the Libya coast guard and navy to save people within their own territorial waters.

Video footage, dated from last September, has since been released depicting Libyan coastguard officers whipping rescued sub-Saharan migrants.

The smugglers and the large number of deaths continues to evade EU stated aims to eradicate both.

Frontex, also known as the European Border and Coast Guard Agency, says some 96 percent of those interviewed who disembarked from Libya had turned to smugglers for help.

At a summit in Malta earlier this month, EU heads of state and government said they remained determined to save lives at sea and break the smuggler's business model.

But the leaders made no mention of creating more legal paths for people to reach the EU.

Discussion on the possibility of issuing humanitarian visas is currently under way among diplomats representing EU states at the Council in Brussels.

The issue has been described as a "red line" by Austria, which opposes visas, in upcoming negotiations with the European Parliament on broader visa code reforms.

The emphasis instead appears to have rescued migrants within territorial waters returned to Libyan shores, where they are likely to end up in prison-like conditions.

Amnesty International's Iverna McGowan has described the EU-led effort as "perhaps the most callous indicator of European leaders turning their back on refugees."

Local Libyan authorities have also voiced objections, noting they have more pressing issues than keeping migrants from leaving the country.