Citing surveys by human right activists, Kyodo news agency said 452 children under the age of 18 were imprisoned as of October last year, nearly double the number held just five years ago.
The two reports -- "Prison Conditions in Cambodia 2005 & 2006" and "Children's Rights in Cambodia" -- document details of prison conditions, including food, health, torture and sexual abuse.
The reports also say 37 children under the age of 6, including 22 infants less than a year old, were living with their mothers in 18 surveyed prisons out of the 25 jails across the country.
"Children who are currently living in prison lack nutrition, provisions and education vital for proper development," the reports say.
Notable deaths of 2014 [PHOTOS]