TRIPOLI, Libya (CNN) -- Four staff members of the International Criminal Court were freed Monday after several weeks of detention in Libya, a Libyan liaison with the court said.

Judge Sang-Hyun Song, the president of the court, met them on their release in the Libyan city of Zintan, said Ahmed Gehani.

Melinda Taylor, a defense lawyer for the ICC, was detained in the city of Zintan after she was discovered carrying documents which the Libyan authorities said jeopardized Libyan national security.

Three other court staff with her at the time have also been held. Taylor, an Australian citizen, is not in jail, but was placed under house arrest.

They were released because they have immunity from prosecution in Libya due to their association with the court.

The Libyan government continues to demand that the ICC investigate the incident and notify the Libyan side of their findings.

Before the release, the Australian government welcomed the news that Taylor appeared close to being freed.

"We're very, very happy for her and for her family," Bob Carr, the Australian foreign minister, said in an interview with Fairfax Radio. "But we'll delay the celebration until she's actually homeward bound."

A search in early June by female Libyan guards after Taylor interviewed Saif al-Islam Gadhafi, a son of the late Libyan dictator Moammar Gadhafi, found documents written by former regime members, according to Gehani, a Libyan lawyer who serves as a liaison with the international court.

The documents included a letter from Mohammed Ismail, Saif Gadhafi's former right-hand man. Taylor was also carrying three blank papers signed by Saif Gadhafi, Gehani said.

Her meeting with Saif Gadhafi, who was captured last November, was authorized by the international court as part of his rights of defense in the case against him.

Both the international court and Libya's new authorities want to put Saif Gadhafi on trial. The court has demanded that Libya hand him over immediately to face accusations of crimes against humanity. Libya appealed the decision, saying that he should be tried at home.

Following negotiations with the Libyan government over the detained staff, the court -- based in The Hague, Netherlands -- issued a statement June 22 saying it "deeply regrets any events that may have given rise to concerns on the part of the Libyan authorities."

It said it had "no intention of doing anything that would undermine the national security of Libya."

CNN's Laura Perez Maestro and Jethro Mullen contributed to this report.