Min Oo, a representative of the Foundation for Education and Development (FED), said that there are questions on the Thai police's work process.
"The deceased fought back her attackers before being killed. The police found clues under her finger nails. They said the clues point to the two suspects and that their DNA matches the evidence. It is questionable that they completed the DNA tests in two days. Did they follow the rules and regulations of conducting DNA tests? Are Myanmar workers being exploited," said Min Oo.
The organisation is now collecting details about the case and sending them to the embassy.
Two migrant workers - Moe Zin Aung and Kyaw Ye Oo - were arrested on October 20 in connection with the murder in Ranong. The victim was stabbed to death on September 28. Three more Myanmar workers were put in police custody.
Sein Htay, chairman of the Myanmar Migrant Worker Rights Network, raised concerns on the rights of the suspects.
"The suspects are underage youths. The police have not let them see their parents since they were arrested. This is a violation of their human rights. The Myanmar government needs to talk to the Thai government about it. They have to put pressure on the Thai government to act in line with law, to allow the suspects to meet their parents, to let their lawyers see them and to use proficient interpreters in the interrogations and in court," said Sein Htay, chairman of the Myanmar Migrant Worker Rights Network.
Earlier, two Myanmar workers were put on trial for the alleged killing of two British backpackers in Koh Tao. Their lawyers pointed several loopholes in the case. The verdict will be heard on December 24.