About 40 Cambodian police and military police received FBI training in interview techniques this week.
Chea Kim, the wife of Ho Sok, says 29 government officials and six judges worked together to sell 13 hectares of land in 1998.
Around 300 managed to apply to be civil parties in Case Three by the 4 p.m. deadline.
Last year, the Cambodian authorities were granted royal pardons for 182 prisoners.
Cambodia is currently ranked as “not free” by the US-based Freedom House, and is ranked 141 of 196 countries by the organization.
Adhoc received more than 200 land dispute cases in 2010, accounting for more than 300 victims.
Sam Rainsy told reporters Sunday he planned a larger demonstration soon.
The Cambodian authorities have banned a public screening of the film, calling it illegal.
The US watchdog Freedom House ranked Cambodia “not free” for 2010, for persecution of and restrictions on journalists.
Sam Rainsy, who lives in exile abroad, is now facing 14 years in jail sentences from a series of criminal suits.
Ouk Seng said Thursday she had made up the allegations because she wanted to return home to her children.
The groups met in Phnom Penh to discuss development plans, foreign aid pledges and Cambodia’s development needs for 2012.