Lithuanian prosecutors said Thursday they have opened an investigation into claims that a Saudi terror suspect was held in an alleged secret CIA jail in the Baltic state.
The probe concerns the "possible illegal transportation of persons across the state border", Vilnius prosecutors said in a statement.
The decision marked a turnaround for Lithuania, which previously refused to probe allegations that 45-year-old Mustafa al-Hawsawi was imprisoned at a secret US Central Intelligence Agency jail there between 2004 and 2006.
A Vilnius court said in January that prosecutors should ask the United States for testimony from Guantanamo detainee Hawsawi before making a final decision on whether to pursue his case.
Human rights activists welcomed the move by prosecutors Thursday, saying it could set an example for other countries facing allegations of hosting secret CIA jails.
"We are pleased with this decision," Meta Adutaviciute of Lithuania's Human Rights Monitoring Institute told AFP.
Sarah Fulton, lawyer at the London-based Redress organisation, told AFP that it was "just the beginning of a long process".
"We certainly hope that it will serve as an example for other countries. And we trust that the investigation will be carried out to get to the bottom of these allegations."
Rights groups said their claims were based on flight data, transfers of other suspects and information about other alleged CIA secret prisons known as "black sites".
Hawsawi is the second terror suspect alleged to have been illegally held in EU and NATO member Lithuania, after top Al-Qaeda operative Abu Zubaydah who is being held indefinitely at Guantanamo.
In 2009, a Lithuanian parliamentary enquiry identified two sites that may have been used as CIA black sites in the Baltic nation.
Prosecutors launched a probe but dropped it in 2011 citing insufficient evidence and a statute of limitations.
The Council of Europe has claimed other secret prisons were also set up in Romania and Poland.
[Image: "Hands Of The Prisoner In Jail" via Shutterstock]