LIBYA has released Australian lawyer Melinda Taylor and three of her colleagues from the International Criminal Court who were detained last month after visiting the son of Muammar Gaddafi.

"The four members (of the ICC team) were released," Ajmi al-Atiri, commander of a brigade holding Gaddafi's son Saif al-Islam told reporters in Zintan, a hilltop town southwest of Tripoli.

Ms Taylor is expected to be reunited with her husband Geoff and their two-year-old daughter Yasmina in The Hague today.

The ICC envoys have been held in Zintan since June 7 after travelling there to help prepare Saif's defence.

Libyan officials said Ms Taylor was detained after being found carrying documents for Saif that were judged a threat to national security.

Ms Taylor's Brisbane-based parents John and Janelle had pleaded with Libya to release their daughter in time for her toddler's third birthday later this month.

Foreign Minister Bob Carr expressed "great relief" about her release.

Senator Carr said Ms Taylor's release came as a result of "fruitful" talks between Libyan authorities and the ICC.

Libyan officials met with the ICC in June and gave a commitment to take all necessary action to release the detained staff.

This came after the ICC said it "deeply regretted any events that may have given rise to concerns on the part of Libyan authorities".

But Senator Carr has also lobbied hard for her release, even visiting the Libyan capital Tripoli last month to press her case.