Despite "constructive" negotiations over jailed Australian lawyer Melinda Taylor, Libya appears to be convinced of her guilt as a conduit for secret communications between Muammar Gaddafi's son Saif al-Islam Gaddafi and hunted members of the former regime.
The case against Taylor was detailed in a letter to the United Nations Security Council obtained by Britain's Guardian newspaper, alleging the use of coded messages and miniature video cameras hidden in a pen and a watch.
Taylor and three other members of an International Criminal Court team were arrested on June 7 during a visit to Saif in the mountain town of Zintan, where he is being held by a powerful local militia.
Foreign Minister Bob Carr, who visited Tripoli last week to push for Taylor's freedom, has adopted what he described as a "muted response during a delicate time".
He said talks between the court and Libyan officials had been very constructive, following a statement from the ICC expressing its deep regret for "any events that may have given rise to concerns" and assurances it did not intend to undermine Libyan national security.
But Carr said he expected Taylor to remain in custody for the foreseeable future.
"I think, and I regret to have to say it, but they [Libyan authorities] will need some time to work this through their political system," he told ABC television.
Negotiations are complicated by tense relations between Libya's transitional Government and the Zintan militia.
The letter obtained by the Guardian supports Libyan belief in Taylor's alleged role in clandestine communications between Saif and former members of his late father's regime.
Taylor and her ICC colleagues met Saif to discuss the appointment of defence counsel for his proposed trial on charges of crimes against humanity, but the Libyan letter to UN Security Council president Li Baodong claims she had committed "blatant violations" of her role.
These included the smuggling of spying devices and a coded letter from Mohammad Ismail, Saif's "main aide" and an associate of Gaddafi's intelligence chief Abdullah al-Senussi, the Guardian reported the Libyan letter as saying.
The letter said Taylor had smuggled a sophisticated miniature "video camera pen" and a watch that "functions for the same purpose", in clear violation of Libya's judicial rules and the moral and professional commitments of the ICC.
"During the meeting, Ms Taylor handed over to the accused [Saif] documents which content [sic] constitutes a threat to the Libyan national security, in the presence of an interpreter," the Guardian quoted the letter as saying.