Ambassador Heidt calls the comments ‘offensive’ and urges an independent probe of the killing.
They decry his rights record and vow to burn him in effigy over the weekend.
Protesters were fired on after they blocked a road following destruction of their homes by plantation workers and police.
Observers have also called on Australia to hold Cambodia to account during an ASEAN summit.
Meanwhile, questions remain over claims that protesters were shot dead by police in the confrontation.
He claims his return to politics has nothing to do with an invitation from Prime Minister Hun Sen.
Woman who told of slain villagers in Kratie land dispute is arrested and recants her story.
Sources say as many as eight people were killed when authorities opened fire on villagers in Kratie province.
Rhona Smith stresses the need to make sure that laws are applied compatibly with international rights standards.
Policy analyst Sophal Ear says Cambodia's debt sustainability is "not bad," but warns against depending too heavily on China as the chief source of the country's borrowing.
The prime minister says he will beat up demonstrators who rally against him when he visits Sydney in mid-March.
A government spokesman says the country will continue to build “democracy” on its own and free from foreign interference.
The Trump administration cites the country's recent Senate elections in which the ruling party swept all seats.
In a vote slammed by observers as illegitimate and unfair, the CPP gains control of Cambodia's upper house.
King Norodom Sihamoni departs for China a day after the Senate approves changes to the charter and a lèse-majesté law.
Cambodians in Australia say Hun Sen's threats are terroristic and ill-advised, as opposition steps of boycott of ruling family companies.
Kem Ley's widow says she is unsatisfied with the handling of the July 2016 daylight murder of her social commentator husband.
Bou Rachana had fled Cambodia with her children following the murder of her husband, a popular social commentator, in July 2016.
The Cambodian National Rescue Movement asks people not to purchase bottled water from a company run by one of Hun Sen’s daughters.
The Interior Ministry is taking legal action against Kem Sokha and others for forming the new Cambodia National Rescue Movement.
They ask the UN human rights agency and other international organizations to help ensure the safety of Sin Chanpeou Rozeth.
Dim Kundy and Hun Vannak had photographed sand dredging carried out by a firm linked to Cambodia's ruling party.
The two have been detained for three months, with no date set for their trial.
In an edited interview, Cambodian opposition figure Sam Rainsy discusses his lawsuit asking Facebook to disclose information on what he calls Prime Minister Hun Sen's false Facebook 'likes.'
Sam Sokha had thrown shoes at a billboard bearing photos of Hun Sen and Heng Samrin, saying the two were 'destroying the country.'
Xiong Bo tells local media accounts of money laundering by Chinese investors are “fake” news.
Tep Vanny was convicted of assaulting security officers during a 2013 protest outside the home of Prime Minister Hun Sen.
Proposed amendments to the constitution are seen as an ‘escalation of authoritarianism’ in the country.
The government move against the paper's website is only now revealed in a letter dated Sept. 28, 2017.
The ruling was made to ensure his safety and the smooth proceeding of his case, according to the court.