Carmelo Zuccaro, the chief prosecutor for the Italian port city of Catania, told "La Stampa" newspaper on Sunday that he has evidence that NGOs are directly working with human smugglers to bring migrants into Italy.

Zuccaro did not offer many details about the evidence his office obtained and did not say whether there would be a criminal investigation.

"We don't know if and how to utilize this information in the judicial process, but we're certain enough of what we're saying: (there are) telephone calls from Libya to some NGOs," said Zuccaro, echoing similar comments he made last month.

Humanitarian aid groups have previously denounced the claims and said if it were not for their work, many more lives would be lost.

"Now and for some time already, the NGOs are saving lives in the sea," Amnesty International official Gianni Rufini told Italian news agency ANSA.

The Italian coast guard has worked alongside NGOs and private vessels just off the coast of Libya to rescue migrants attempting to cross the Mediterranean Sea into Europe. They rescued thousands of migrants in flimsy dinghies and small wooden boats over Easter weekend.

Zuccaro said that not all NGOs that work with the Italian coast guard in the Mediterranean are working with human smugglers.

"For the suspect (NGOs), we must understand what they do; for the good ones, instead one must ask if it's right and normal that European governments leave the task of decided how and where to intervene in the Mediterranean to them," said Zuccaro.

There has been a dramatic uptick in migrants attempting the dangerous trip from Libya to Italy so far this year. About 36,000 migrants have been rescued in the Mediterranean Sea in 2017, an approximately 44 percent increase at this point in the year from one year ago. At least 1,000 migrants have died attempting the sea crossing so far in 2017, according to the International Organization for Migration (IOM). Zuccaro said that up to 250,000 migrants could arrive on Italian shores by the end of the year if the pace continues.

Italian Prime Minister Paolo warned against criminalizing NGOs on Friday, saying they "save lives and should be thanked."

Populists agree with claims

Italy is due to have their next general election before summer 2018. With decreasing support for the NGOs in Italy, the populist parties and leaders are also denouncing the work of the NGOs.

Luigi Di Maio, a top leader in the populist 5-star Movement, said the NGOs are "in cahoots with human traffickers," adding, "we want light shed on this, to know who finances (the NGOs)."

The party also called the NGOs work a "taxi service" for migrants, similar to claims from the Northern League and Forza Italia parties known for their populist policies.

Many Italian polls currently give the 5-star Movement a slight lead over the ruling center-left Democratic Party.

kbd/bw (AP, Reuters)