Demonstrators hold a banner reading "Free Carola" during a vigil on July 2 | Federico Gambarini/AFP via Getty Images Italian judge frees Sea-Watch captain Interior Minister Matteo Salvini reacts with fury.

An Italian judge ruled Tuesday that German Sea-Watch 3 captain Carola Rackete did not break the law when she docked her migrant rescue ship on the island of Lampedusa without permission.

The judge found an Italian security decree is "not applicable in the case of rescues," referring to the migrants who were on board the vessel, AFP reported. Rackete was carrying out her duty to save lives, the judge said, clearing her of the charge that she endangered a patrol boat while docking in Lampedusa, which carried a potential jail sentence of up to 10 years.

The ruling frees Rackete from house arrest, but she is still due to appear in court again on July 9 to face questioning over charges relating to aiding illegal immigration.

Italy's far-right Interior Minister Matteo Salvini reacted to the ruling with fury, tweeting: "For the Italian judiciary, ignoring the laws and ramming a patrol boat ... are not sufficient reasons to go to jail."

Salvini, who is also Italy's co-deputy prime minister, promised to deport the German captain as soon as possible, calling her a "danger to national security," according to AFP. She is unlikely to be expelled from the country prior to her court appearance.

Sea-Watch International said Wednesday it had moved the German skipper to a secret location due to threats to her safety, according to Reuters.

"I was relieved about the judge's decision, which I see as a big win for solidarity with all people on the move including refugees, migrants and asylum seekers, and against the criminalization of helpers in many countries across Europe," Rackete said in a statement released by Sea-Watch International.

Rackete's case attracted significant international attention, with over €1 million raised to help fund her legal defense. According to Reuters, the money will be used to support future rescues.