The government had reclassified four economic land concessions as state property, reclaiming almost 20,000 hectares earlier handed to private firms to use for rubber plantations.
A sub-decree issued on August 31 said the land in Kratie, Kampong Thom and Ratanakkiri provinces was to be taken back from four companies following an Agriculture Ministry proposal in March.
The companies were all supposed to develop rubber plantations, but failed to do so, clearing the land and then abandoning it.
Firms have in the past been accused of carrying out such land clearances to profit from timber sales.
Dong Nai Company was earlier granted 6,523 hectares in Kratie, while Dong Phu Company, received 1,949 hectares in the province.
CRCK Company was given 5,272 hectares in Kampong Thom province, while Krong Buk Company had 6,051 hectares in Rattankiri province.
In March last year, CNRP lawmaker Um Sam An sent a letter to Prime Minister Hun Sen demanding an explanation of media reports that claimed the Vietnamese military had received 40,000 hectares of land as a secret economic land concession in Ratanakkiri.
Mr Hun Sen’s government has issued concessions for more than 2.1 million hectares of land to investors, including major Chinese and Vietnamese companies and local firms, according to a 2015 report by the human rights group Licadho.
The government last year said it would take back about 1 million hectares from investment companies that had been granted land concessions.
At the time, Mr Hun Sen said the land would be doled out to the poor, while the government also reduced the duration of economic land concession investments from 90 to 50 years.
Neither the private firms behind the land concessions nor the Agriculture Ministry could be reached for comment yesterday.