Italian far-right deputy prime minister Matteo Salvini is under investigation for “kidnapping” a group of migrants aboard a coast guard vessel.

Prosecutors in Sicily confirmed the probe into Salvini’s actions after he refused to let the rescued migrants off the coastguard ship which berthed in Catania unless the EU committed to taking some of them.

Salvini theatrically opened a letter with an official notice from Palermo’s Chief Prosecutor Francesco Lo Voi in a live Facebook video in which he claimed that he risked “at least 15 years in prison.”

The dogged Salvini said he was ready to be interrogated, but promised his social media followers he would “not budge an inch.”

Italy’s far-right and populist government insisted that Malta should take the group because their boat first passed through its search-and-rescue area, but Valletta refused, claiming the people wanted to reach Italy.

Questioned by the Italian authorities, the 13 people evacuated claimed the Maltese had escorted them outside its search-and-rescue zone, Rome said.

The ship picked up 190 people from an overcrowded boat about 17 sea miles from the island of Lampedusa. Thirteen of them were evacuated for emergency medical treatment but the rest were denied disembarkation for 10 days.

The standoff came to an end after Albania accepted to take 20 people aboard the ship and the Catholic Church in Italy said it would take in 100 people.

However, 50 of the migrants vanished from Italian reception centres in Italy with Salvini, saying the “disappearance” of the migrants is another piece of evidence that they do not need his country’s help.

However, some of the hosts say the migrants didn’t vanish, that they left on their own accord, and with good reason.

“It is a voluntary departure, not an escape, one flees from a state of detention and this is not the case, nobody wants to stay in Italy, you know,” director of Caritas Italiana, Francesco Soddu, told ANSA.