Italian prosecutors have opened an investigation into the illegal detention of 177 migrants onboard a coastguard vessel that the minister of the interior, Matteo Salvini, refuses to allow to land.

The Ubaldo Diciotti has been docked for 48 hours at the port of Catania, Sicily, but the majority of the migrants have not been allowed to disembark without having guarantees from Brussels on their distribution to other countries.

The investigation, conducted by the prosecutor of the city of Agrigento, was launched against “unknowns” but it is clear that if the magistrates were to go ahead with a judicial proceeding, Salvini would end up under investigation, being the only one responsible for the landing ban.

“I heard that the prosecutor’s office in Agrigento has opened an investigation,” said Salvini in a recent video on Facebook Live.

“I also heard that the suspects are ‘unknown’ at the moment. But I’m not unknown. My name is Matteo Salvini, I’m the minister of the interior. Come on, try me too, I’m here.”

The Ubaldo Diciotti docked on Monday night in the port of Catania but the 177 migrants onboard, including 29 unaccompanied minors, were refused authorisation to disembark.

The ship picked up 190 people on 15 August from an overcrowded boat about 17 nautical miles from the Italian island of Lampedusa. Thirteen of them were evacuated for emergency medical treatment.

Rome insisted that Malta should take the group because the boat first passed through its search-and-rescue area, but Valletta refused, claiming the people wanted to reach Italy.

When questioned by the Italian authorities, the 13 people evacuated claimed the Maltese had escorted them outside Malta’s search-and-rescue zone.

On Monday afternoon, after three days of negotiations, Italy’s transport minister, Danilo Toninelli, tweeted: “The Diciotti ship will dock in Catania.”



However, shortly afterwards, Salvini’s press officer said the interior minister had “not given and will not give the authorisation for the migrants to disembark until he is assured that the 177 migrants will go elsewhere”, barring Italy’s own coastguards from landing the migrants.

On Wednesday afternoon, prosecutors in Agrigento visited the ship and questioned the captain and several migrants.

“There are migrants onboard clearly affected by scabies,” said the chief prosecutor, Luigi Patronaggio. “They require urgent medical assistance. The situation onboard is critical.”

Following the magistrates’ visit, Salvini authorised on Wednesday night for the 29 unaccompanied minors to disembark, but made it clear he would not authorise the landing of the remaining 148 asylum seekers onboard “unless Europe steps in”.