The Cambodian parliament has passed a bill that criminalises the denial of atrocities committed by the Khmer Rouge.
Individuals found guilty face a maximum sentence of two years imprisonment under the new law.
Human rights organisations have said that the law is an election stunt and could be used against the political opposition by Prime Minister Hun Sen.
"It's a tool to try to intimidate the opposition but also to galvanise his side, to demonise the opposition as unfit to govern, and to show that he's in charge, to show the country that he can completely dominate the opposition - and make them squirm," Brad Adams of Human Rights Watch said.
