The government estimates some 730 juvenile prisoners—those aged between 14 and 17—are incarcerated in the country’s 25 prisons.
The major increase in counter-narcotics has come this year, with 475 alleged drug offenders already arrested.
The petition drives comes as the UN’s special human rights envoy for Cambodia, Surya Subedi, arrives in Phnom Penh on Monday.
Subedi is also expected to speak directly with residents in the Beoung Kak lake dispute.
Cambodia has been influenced largely by the French and the Chinese in its modern history, with China’s influence growing today.
Rights officials said that the order was understandable during ongoing operations, but that it could be abused.
Moeung Sonn, who has fled the country, is facing a two-year prison sentence following a suit brought by the government in 2009.
About 40 Cambodian police and military police received FBI training in interview techniques this week.
Chea Kim, the wife of Ho Sok, says 29 government officials and six judges worked together to sell 13 hectares of land in 1998.
Around 300 managed to apply to be civil parties in Case Three by the 4 p.m. deadline.
Last year, the Cambodian authorities were granted royal pardons for 182 prisoners.
Cambodia is currently ranked as “not free” by the US-based Freedom House, and is ranked 141 of 196 countries by the organization.