Kem Ley's supporters are still calling for an independent inquiry into his murder.
The CNRP was banned by the Supreme Court late last year and will not be able to field any candidates to contest seats in the July 29 election.
At each event, the premier’s team handed out about $5 to each attendee, making the total sum in the region of $3.5 million, according to the government’s figures.
Zhao’s visit comes after a visit to the country by Wei Fenghe, Chinese defense minister, where he signed off on some $100 million worth of military deals with Phnom Penh.
Brad Adams told VOA the report was based purely on historical facts, which the Cambodian authorities had not challenged with any counter-evidence, adding that Hun Sen should produce evidence to support his claim that his generals were “clean”.
Hun Sen has said that people posting online messages online saying they will not vote in the election on July 29 could face legal action.
In a white paper issued in January, China identifies itself as a “Near-Arctic State”, a term not fully recognized in law.
Representatives of major mobile phone operators covered by the order could not be reached for comment.
Ouk Phalla was one of the country’s most prominent Apsara dancers.
The HRW report said 12 security officers formed the backbone of Hun Sen’s “abusive and authoritarian political regime” and had “demonstrated a willingness to commit rights abuses on behalf of Hun Sen.”
Two candidates in next month’s election amongst those targeted in new report.