European parliamentarians have accused the Lao authorities of telling them "ridiculous lies" in relation to the disappearance of leading civil society figure Sombath Somphone.
He was last seen in December when CCTV footage showed him being stopped at a police checkpoint and forcibly bundled into another car.
Authorities say that they cannot find Mr Sombath despite the video evidence.
Laos has been run by the Communist party since 1975.
Both civil society and media are tightly controlled.
Eight months after his disappearance there is still no information about what happened to Sombath Somphone.
This was the third parliamentary delegation from the European Union to travel to the capital, Vientiane.
As with the other two - the Lao authorities told them they had made no progress but rejected offers of technical help.
The Danish head of the delegation, Soren Bo Sondergard, said it was clear from their discussions that the Lao authorities were in denial and at times had told them "ridiculous lies".
Lao police say they have not been able to identify any of the people or vehicles involved in Mr Sombath's abduction.
Many believe that he was taken by elements within the security establishment - angered by his role in organising the Asia-Europe People's Forum in October last year.
Lao society and public debate is tightly controlled and at the time the Forum was seen as an unprecedented opening up of political space.