The Phnom Penh Municipal Court ruled in December to jail Yorm Bopha, an activist from the embattled neighborhood of Boeung Kak lake, for three years.
Over the last year, families that were evicted from the neighborhood have lived in tents outside the city, far from businesses, health care, schools and clean water.
The refugee office has seen its operations vastly reduced after the influx of Montagnard refugees tapered off in recent years, following a change in the way the US grants asylum.
Protesters say the assailant was in fact Chhouk Bandith, but the courts have dropped charges against him.
Brother of slain activist Chea Vichea said he no longer believes the judiciary can provide justice for the murder of his brother.
Demonstrators against the Boeung Kak lake development gathered in front of the Phnom Penh court on Monday, demanding charges dropped against a woman and her husband who are activists against forced evictions.
Born Samnang and Sok Samoeun were remanded to 20-year prison sentences by the Appeals Court on Thursday, following their release on the order of retrial in 2009.
Thai authorities say they plan to kick out illegal workers in the near future, this include some 160,000 Cambodians.
Rights activists say the case not only demonstrates Cambodia’s culture of impunity, but also its gender inequality.
Both activists were charged under a new penal code for “aggravating circumstances” in the alleged assault of two men in August.
The court’s decision set off a new round of outrage from local and international rights groups and others in the international community.