Illegal migrants from Nigeria account for 21 per cent of the total 171, 299 immigrants that crossed the Mediterranean to arrive Italy last year.
Figures from the Italian Interior Ministry estimated the record of Nigerian arrivals at 36,000, with most of them claiming they were running away from Boko Haram insurgency or Niger Delta crisis.
The estimate was as at November 2016.
News Agency of Nigeria (NAN) said the Nigerian government was briefed by the Italian authorities on this development late last year.
In a report published December 9, Frontex, the European Union border agency, some 181,000 migrants eventually arrived in Italy last year from North Africa, the highest number ever recorded. It was 20 per cent more than last year.
The largest group of migrants arriving were Nigerians, Eritreans and Guineans, the agency added.
Nigerians, along with Guineans also formed the bulk of migrants rescued at sea, especially in November, said Frontex.
The flow of Nigerian immigrants to Italy via the Mediterranean backdoor began in 2008 and declined for five years. From 2013, the number jumped.
In sorting out the migrants, Italian and European authorities have been able to distinguish between migrants from war torn states such as Syria from the hordes of economic refugees from Africa.
“The flow from Syria and Iraq is somewhat contingent while that from Africa is structural.
Some European citizens support welcoming refugees from Syria while support for African economic migrants among public opinion is extremely low,” Mattia Toaldo, senior policy fellow at the European Council on Foreign Relations said.
Italy meanwhile, has reopened its embassy in Libya to enable its officials work with Libyan government to stem the flow of immigrants, through the Libyan route, the most popularly used by Nigerian migrants.
The Italian Interior Minister Marco Minniti announced the decision on Monday.
The embassy was closed down in 2015, along with all other Western embassies as the North African country descended into violence.