After a spouse has been selected, a go-between discusses the proposal with the parents, who need to be satisfied that the right choice is being made for their offspring.
Presents are exchanged, and in rural areas, a young man may have to vow to serve his new father-in-law for a while. It starts at the bride's home followed by a religious ceremony and exchange of ritual gifts.
The report was a follow-up to a 2013 story on the same subject.
Prime Minister Hun Sen, speaking at a graduation ceremony, singled out the program's reporting that Cambodian mothers sold their daughters into prostitution as particularly insulting, although the 2013 story by CNN had previously reported that.
Human rights groups allege that he and his business friends are enriching themselves, while most of the population remains mired in poverty. The king is surrounded by the government's watchdogs, overseen by Minister of Royal Affairs Kong Som Ol, an official close to Hun Sen.
Sihamoni is closely chaperoned on his few trips outside palace walls, with the media kept away.
A girl who becomes pregnant out of wedlock is seen as bringing shame to her family.
Hun Sen said he "could not accept" the assertion that Cambodian mothers sold their daughters into prostitution.Much of the controversy involved the ethnicity of the three young women the CNN report focused on.They appeared to be ethnic Vietnamese rather than Cambodia's mainstream ethnic Khmer.Now, close aides and experts say, he has become figuratively, and more, a prisoner in his own palace.The chief warden: Prime Minister Hun Sen, who rose from a poor rural background to become a brilliant and crafty, some say ruthless, politician.