The United Nations Human Rights Council (UNHRC) has appointed activist Angkhana Neelaphaijit as a member of its Working Group on Enforced or Involuntary Disappearances (WGEID), according to the UN.
In a tweet, the UNHRC said Ms Angkhana was named a WGEID member during the 49th session of its meeting to select members.
According to the UNHRC website, WGEID's primary task is to assist families in determining the fate or whereabouts of those who have disappeared.
The group is meant to serve as a channel of communication between victims' family members, people reporting disappearance cases and the government, it said.
Ms Angkhana, a former nurse, became an activist following the 2004 disappearance of her husband Somchai Neelapaijit, a human rights lawyer.
She founded the Justice for Peace Foundation in 2006, and the network has played a key role in documenting the human rights situation in southern Thailand.
She was selected as a member of the National Human Rights Commission in 2015 and resigned in 2019 along with another member, claiming the working environment was not conducive for them to perform effectively.
Ms Angkhana has received an award in recognition of her fight for human rights from the Asian Human Rights Commission. She received the Ramon Magsaysay Award in 2019, after being lauded for "championing justice, case after painful case", according to the foundation's website.