The Cambodian appeal court agreed with the Phnom Penh court that the three Jemiah Islamiyah terrorist suspects should remain in jail.
The three foreign suspects, two Thais and one Egyptian, have been in jail for two years without trial even though the Cambodian law says the court can not hold a suspect without trial longer than six months.
The men's lawyer has requested the court to free his clients without success.
Both the Phnom Penh court and the appeal court said the three men can not be freed on bonds because they pose security risks to both the Cambodian and the international community because they are terrorist suspects.