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'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.
The three other detained ICC staffers are Taylor's interpreter from Lebanon, Russia and Spain.
Fadi el-Abdallah only said that the ICC president, South Korea's Sang-Hyun Song, would travel to Tripoli with a delegation but did not provide more details.
Australian Foreign Minister Bob Carr had 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 would 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.
The ICC wants to try Seif al-Islam, 39, for crimes against humanity during his father's rule, which came to an abrupt end last year.
Tripoli insists he should be tried locally and filed on May 1 a motion challenging the ICC's jurisdiction to put him on trial in The Hague.
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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.
The three other detained ICC staffers are Taylor's interpreter from Lebanon, Russia and Spain.
Fadi el-Abdallah only said that the ICC president, South Korea's Sang-Hyun Song, would travel to Tripoli with a delegation but did not provide more details.
Australian Foreign Minister Bob Carr had 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 would 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.
The ICC wants to try Seif al-Islam, 39, for crimes against humanity during his father's rule, which came to an abrupt end last year.
Tripoli insists he should be tried locally and filed on May 1 a motion challenging the ICC's jurisdiction to put him on trial in The Hague.
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