Libya has put four International Criminal Court (ICC) envoys in "preventive" detention in prison for 45 days while investigating an alleged threat to national security, a judicial source said on Monday.
"A decision was made to put them in preventive detention for 45 days while investigations are conducted," an official in the attorney general's office told AFP on condition of anonymity.
Ajmi al-Atiri, head of the brigade that detained the delegation after it visited Muammar Gaddafi's son Seif al-Islam, said: "They were transferred yesterday (Sunday) to a prison on the orders of the prosecutor general."
The four-member delegation is being held in the western town of Zintan after one of its lawyers, Melinda Taylor, was found carrying documents for Seif al-Islam that were considered a "threat to national security."
Ahmed Jehani, Libya's envoy to the ICC, has said that the Australian lawyer was caught "exchanging papers with the accused Seif al-Islam."
Jehani alleged that Taylor was carrying a pen camera and a letter from Mohammed Ismail, Seif's former right-hand man who is now on the run.
He said the letter contained drawings and symbols, a "code" that would be understood only by the sender and the intended recipient, Seif.
"According to Libyan law, it would be spying, communication with the enemy," the envoy said.
Jehani said that her interpreter Helene Assaf, a Lebanese who has been working with the ICC since 2005, was considered an "accomplice."
The ICC has named the other members on the team as Russian Alexander Khodakov and Esteban Peralta Losilla from Spain.
The team was in Libya to help Seif choose a defence lawyer, and the court has said that the visit was authorised by Libya's chief prosecutors. The ICC wants to try Seif, 39, for crimes against humanity in The Hague.
But the new regime in Libya wants to put Seif on trial in a local court, while ex-rebels in Zintan who are holding Kadhafi's son are refusing to send him to Tripoli for fear that he might escape.