The European Parliament announced Thursday its "strong concern" for a prominent Laos activist missing since December, calling on the government to speed up its investigation into the disappearance.
In a resolution adopted by the parliament, European deputies called on Laos authorities to "undertake prompt, transparent and thorough investigations" into the fate of Sombath Somphone.
The resolution called for the "immediate and safe return" of Sombath to his family.
The 62-year-old founder of the Participatory Development Training Centre (PADETC) -- a non-governmental organisation campaigning for sustainable development -- went missing on December 15 while driving home in the capital Vientiane.
Images from CCTV cameras, obtained by Sombath's family and published online, show him being taken away from a police post by two unidentified individuals. He has not been seen since.
The communist regime has vowed it had nothing to do with his disappearance but the case has nevertheless sent chills through civil society.
"The Lao government must take all necessary steps to end the practice of arbitrary arrests and secret detention," the parliament said, denouncing attempts to limit individual, press and religious freedoms.
In recent weeks both former US secretary of state Hillary Clinton and the EU's foreign policy chief Catherine Ashton called on the Southeast Asian nation to ensure Sombath's safety.