Sydney - Australian Foreign Minister Bob Carr on Thursday called for the release of an aid worker being prevented from leaving Libya over a police investigation involving a senior official.
Australian national Alexandra Bean, an employee of the International Organisation for Migration, had been refused permission to leave Libya after being questioned in an "investigation into an official", Carr said.
Bean's brother James said she had been stopped at Tripoli airport and had her passport confiscated after being questioned over sexual assault allegations against a senior health official.
"They're obviously seeking to question her and they've got some questioning to continue and they don't want her to leave the country out of a concern that she won't return," Carr told reporters.
"I think she ought to have the right, she ought to be in the position to... to leave the country as she wants, and we will continue to make representations about that."
James Bean said his sister "needs help".
"Given what's happened with Chris Stevens and three other US officials in Benghazi this is a very fluid environment, very uncertain," he told ABC radio.
Stevens, the US ambassador to Libya, and three other Americans were killed in violent demonstrations earlier this month against an anti-Islam film which has triggered anger across the Muslim world.
Carr said Australia's envoy in Cairo had been in contact with Bean and she would "continue to be a focus of our work and... further representations to the government of Libya about her capacity to leave the country".
But he said a diplomat would not be sent to Libya to assist her, nor would the Australian government provide legal help.
"Australia does not provide its nationals overseas in trouble with foreign jurisdictions with legal assistance... It's not our practice to send lawyers in," said Carr.
"We will provide in this case, as we do in all comparable cases, consular assistance."
An Australian lawyer working for the International Criminal Court was detained in Libya for three weeks earlier this year after visiting a son of former dictator Muammar Gaddafi in the town of Zintan, southwest of Tripoli.