On Saturday, Mediterranea’s Italian-flagged Alex arrived in the port where a strong police presence was waiting for them.
“In view of the intolerable hygiene conditions aboard, the Alex has declared a state of emergency and is sailing towards Lampedusa, the only possible safe port for landing,” Mediterranea said in a tweet earlier.
According to RAI public television, who had a journalist on board, Alex ran out of water. The boat also looked overcrowded.
In a statement, Mediterranea said that its vessel has a legal capacity of 18 people, but was currently hosting nearly 60 people, including 41 migrants.
TV footage showed the sailboat enter the port escorted by Italian police units, with the migrants on deck, wearing orange life jackets.
Police and other officials could be seen at the docking point, but nobody was let off the boat, and it was not immediately clear when that would happen.
“The rescued migrants now have to be immediately disembarked and given medical assistance. Let them off,” Mediterranea tweeted, stressing it acted out of a “state of necessity”.
The Italian government had asked Mediterranea to head to Malta, but the NGO said the 11-hour journey would have been too long and dangerous.
“[With Malta available] I can’t understand why these traffickers should decide where to go or not to go,” Salvini said in Milan.
“Police forces are ready to intervene” against Alex, Salvini said in a later statement. “In a normal country, arrests [for the crew] and seizure of the boat would be immediate,” he added.
Mediterranea said it asked Malta permission for the migrants to be taken to Valletta port by a larger charity vessel, Open Arms, but Malta refused this.
Authorities on Lampedusa last week seized another rescue ship belonging to German aid group Sea-Watch after it forced its way into port with dozens of rescued migrants on board and arrested its captain, Carola Rackete.
An Italian judge this week ordered her freed as she had been acting to save lives, a decision which sparked Salvini’s ire but may have encouraged the Alex crew.
Two other investigations, on charges of helping people smugglers and resisting the authorities are still under way after Rackete forced her way past Italian customs vessels.
A third rescue ship, German charity Sea-Eye’s vessel Alan Kurdi, carrying 65 shipwrecked migrants rescued off Libya on Saturday arrived and held its position in international waters off Lampedusa.
Last month Italy passed a decree, spearheaded by Salvini and his far-right League party, foreseeing hefty fines for migrant NGO which trespass into Italian waters.