Sam Rainsy remains in exile abroad and was not present for the hearing, which lasted from 8 am to 1:30 pm amid heightened security.
The general strike, which will hit Cambodia's main economic earner, is scheduled for Sept. 13 through Sept. 18.
Villagers in Kampong Speu province have alleged that sugar plantations operated by Ly Yong Phat have pushed them off their land.
The Cambodian government is facing more accusations it has cracked down on freedoms of expression and the media in the past years.
Four men including a human rights worker received lengthy jail sentences in Takeo province Monday.
She also called for sufficient lawyers to provide legal services to the people.
Other court observers say the government lacks the political will to reform the judiciary or overcome Cambodia's culture of impunity.