Family members and followers of the disappeared Khmer Kampuchea Krom monk, Tim Sokhorn, have asked that aid agencies help find him.
Tim Sokhorn has been missing for more than two weeks, and rights groups fear he was forcibly taken from his Takeo province pagoda and possibly expelled to Vietnam.
About 50 people gathered in Takeo on Thursday to travel to Phnom Penh and appeal to aid groups for help finding the monk, who was defrocked for allegedly fomenting unrest between Vietnam and Cambodia.
Tim Sokhorn's father, Tim Theang, said he was worried over whether his son was alive or dead.
"My son has been missing since [June 30]. I have not received any news about him," he said.
"Where did he go? Is he dead or alive? I would like to know," said follower Neath Pov, an elderly woman.
Venerable Chin Sinath, acting president of North Phnom Den temple, said Tip Sokhorn did not have affairs with women, as alleged by television and a government spokesman in the days following his disappearance.
Takeo province Adhoc investigator Ouch Leng said he was suspicious of local government and security forces after they told villagers to stay out of the affairs of the Khmer Krom, an ethnic minority group living along the Mekong River in Vietnam and Cambodia.
"Another reason is that the checkpoint police and the communal chief threatened the villagers not to get involved with the Khmer Kampuchea Krom movement," he said. "The temple committee and the villagers are afraid because of the checkpoint police threats."