The United Nations (UN) Human Rights Office has expressed concern that the disappearance of pastor Raymond Koh and activist Amri Che Mat is linked to their community work.

"We are gravely concerned for the safety and well being of the two men and we fear they may have been abducted due to their community work.

"We call on the Malaysian government to conduct a prompt investigation to establish their whereabouts and to keep their families informed of any developments," UN Human Rights Office acting regional representative Laurent Meillan said in a statement today.

Koh's family has previously brought the matter to the UN working group on enforced or involuntary disappearances (WGEID)...