The International Criminal Court's president was headed to Tripoli on Monday as court officials said Libya was poised to free a legal team detained after visiting slain leader Moamer Kadhafi's jailed son.
South Korea's Sang-Hyun Song was expected to land at Tripoli's Metiga military airport at 11:30 am (0930 GMT) and head immediately to the town of Zintan, where the team was being held, a Libyan protocol official told AFP.
Fadi el-Abdallah, spokesman of The Hague-based tribunal, said earlier Song would travel to Libya where the "release of the four ICC staff member" was expected on Monday.
Libya's envoy to the ICC confirmed that the release of the team was imminent.
"If the ICC president arrives today (as scheduled), it is sure they will be released today," Ahmed Jehani told AFP.
"The transfer of the team from Zintan to Tripoli must take place during the day," for security reasons, he added.
The four, including Australian lawyer Melinda Taylor, have been held in Zintan, southwest of Tripoli, since June 7 after travelling there to help prepare Seif al-Islam Kadhafi's defence.
Taylor was accused of carrying a pen camera and attempting to give Seif al-Islam a coded letter from his former right-hand man, Mohammed Ismail, who is wanted by the Libyan authorities.
Libya accused the team of "breaching national security."
The other three detained ICC staffers are Taylor's interpreter from Lebanon, Helen Assaf, and two colleagues, Russian Alexander Khodakov and Esteban Peralta Losilla from Spain.
Australian Foreign Minister Bob Carr said Monday his advice from the ICC was that Taylor and her colleagues were expected to be released at about 1000 or 1100 GMT.
"This is all based on the advice from the International Criminal Court; They will breathe easy when it's fulfilled and she's winging her way on the promised Italian military jet to her home in The Hague," Carr told Australia's Sky News.
"But so far it's very good news, a great relief."
The breakthrough came about through "fruitful negotiations" between the ICC and Libyan authorities, he said.
The ICC wants to try Seif al-Islam, 39, for crimes against humanity allegedly committed last year when his father's regime attempted in vain to crush a popular uprising.
Tripoli insists he should be tried before a Libyan court and filed a motion on May 1 challenging the jurisdiction of the Hague-based court.
Carr said a week ago that talks in The Hague between the ICC and the Libyan authorities had resulted in "the ICC expressing regret, effectively an apology for any misunderstandings".
The ICC has stopped short of admitting to any wrongdoing but has said it will fully investigate its team's behaviour upon their return.
"When the ICC has completed its investigation, the Court will ensure that anyone found responsible for any misconduct will be subject to appropriate sanctions," it added in a statement issued last month.