The Italian prime minister announced the investigation on social media, saying, “I cannot be blackmailed.”
Prime Minister Giorgia Meloni of Italy announced on Tuesday that she was being investigated by Italian prosecutors for her alleged role in aiding and abetting the release last week of a Libyan official wanted on war crimes charges.
The case focused on Italy’s arrest and quick release of Osama Elmasry Njeem, the director of several Libyan prisons known for their inhumane conditions.
Last week, the Italian police arrested Mr. Njeem in a Turin hotel room after the International Criminal Court in The Hague issued an international warrant. Mr. Njeem was wanted in connection with crimes against humanity, including murder, torture, rape and sexual violence.
Shortly after he was arrested, Mr. Njeem was released for what the Italian authorities called a procedural issue. He was then taken back to Libya on a government plane.
His release set off an outcry by human rights groups and opposition leaders, who accused Ms. Meloni of cozying up to the Libyan authorities because Italy relied on Libya to keep migrants from Italian shores.
The International Criminal Court also objected, issuing a statement recalling “the duty of all States Parties to cooperate fully with the Court in its investigations and prosecutions of crimes.” It said it had asked the Italian authorities to clarify their actions.