Two East Timorese journalists are going on trial in a criminal defamation case brought by the country's prime minister that has alarmed rights groups.

Raimundos Oki and his former boss Lourenco Vicente Martins are charged with "slanderous denunciation" and face up to three years in prison if found guilty. The trial is set to begin Friday.

Rights groups and press advocates have urged that the case be dropped.

Oki and Martins published a story in the Timor Post last year about Prime Minister Rui Aria de Araujo's involvement in a state telecommunications contract when he was an adviser to East Timor's finance minister in 2014.

There was a factual error in the story that the newspaper apologized for.