Libya has released four International Criminal Court staff who had been held for nearly four weeks over allegations that they shared documents that could harm national security with Muammar Gaddafi's imprisoned son Saif al-Islam Gaddafi.
As they were released, ICC President Sang-Hyun Song, a South Korean judge, apologised to the Libyan government and people for the incident and promised an investigation into the allegations.
Mr Song, who flew to Libya for the handover, said: "The ICC is grateful to the Libyan authorities for their agreement today to release the Court's staff members so that they can be reunited with their families."
A special flight arranged by the Italian government and carrying Mr Song and the staff landed at Rome's Ciampino airport late on Monday. The staff and Mr Song took off for Rotterdam a few minutes later.
"Well, I'm very happy to bring them all back to freedom," the court president said. "The Libyan government gave me their version of the investigation. We will do our own separately, so the results will be known after some weeks."
Libyan authorities say they placed Australian defence lawyer Melinda Taylor and her Lebanese translator under house arrest after they visited Saif al-Islam in prison in the western town of Zintan and allegedly shared documents that could harm the country's national security.
Saif al-Islam was the most senior member of the ousted Gaddafi regime to be captured in last year's conflict. Long viewed as the heir-apparent to his father, he faces charges from the ICC of crimes against humanity.
He was captured by a militia in western Libya after his father was taken captive and then killed last October following more than 40 years as Libya's authoritarian ruler. Libya's new leadership accuse Saif al-Islam of torturing and killing rebels, as well as other crimes.
His trial has been at the heart of a dispute between the ICC and the Libyan government. Authorities challenge the ICC's right to try him, saying the court is a tribunal of last resort, intended to try suspects from countries that cannot or will not prosecute them. The court is concerned Libya's judiciary is not yet ready to give Seif al-Islam a fair trial.
Richard Dicker, international justice programme director at Human Rights Watch, said the release of the ICC employees was "overdue" and if Libya had concerns over their conduct it should have submitted a complaint to the ICC. Amnesty International urged the ICC to investigate the legality of the detention and the allegations against its staff.