(CNN) -- Foreign Minister Bob Carr of Australia is visiting Libya on Monday to step up pressure on officials there to release an Australian lawyer working for the International Criminal Court who was detained after visiting the son of the late Libyan dictator Moammar Gadhafi.
Melinda Taylor, a defense lawyer for the international court, was detained in the city of Zintan after she was discovered carrying documents that the Libyan authorities said jeopardized Libyan national security.
A search by female guards after Taylor interviewed Saif al-Islam Gadhafi, who was captured last November, found documents written by former regime members, according to Ahmed Gehani, a Libyan lawyer who serves as a liaison with the criminal court in The Hague, Netherlands.
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 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.
Taylor is not in jail, but was placed under house arrest in Zintan, along with a translator. Gehani said the Libyan authorities are looking into whether she was spying and communicating with the enemy.
Carr said in a statement that he had "modest expectations" for the talks Monday because the Libyan foreign minister had advised that Taylor was facing an investigative process.
"But we will press the case that Ms Taylor is in Libya under the mandate of the ICC and United Nations Security Council, and this mandate provides a legal immunity," Carr said. "It is Australia's view that Ms Taylor should be afforded consular access, and should no longer be detained."
The two other court members from the registry office of the international court were not held by the Libyan authorities but chose to remain with Taylor and the translator in Zintan.
Carr is in the Mediterranean region for meetings in Turkey, Algeria and Morocco.
Officials from the International Criminal Court met with the four staff members last week, along with ambassadors from their different countries.
Taylor and the other court staff "indicated that they were in good health and well treated," the court said in a statement.
The court "welcomes the assistance provided by the Libyan authorities to date," it said, and is eager "to address any regrettable misunderstandings on either side about the delegation's mandate and activities during its mission in Libya."
It said that as a suspect, Said Gadhafi has the right to "communicate freely and in confidence with his lawyer."
"Such communication," it said, "may include discussing and exchanging documents and discussing potential witnesses and defence positions in the case."
The international court has issued an arrest warrant for Saif Gadhafi on charges of crimes against humanity. He stands accused of having a role in the deaths of Libyans who protested his father's 42 years of dictatorship.
Taylor and lawyer Xavier-Jean Keita said in April that Saif Gadhafi has been mistreated and "physically attacked" since his capture.
In a strongly worded statement, the lawyers described Gadhafi as being in a legal black hole, held in total isolation except for visits from officials. He also suffers dental pain because he hasn't had treatment, and Libyan authorities have given him nothing to remedy the pain, the lawyers said.