The government said Tuesday that the documentary's content is a threat to national security and international relations, The Hollywood Reporter said.
"Boundary" begins with footage of the political protests in Bangkok that occurred in 2011 and resulted in the deaths of nearly 100 people.
Numbenchapol then zeroes in on one of the soldiers involved in the dispute and follows him to his hometown on the border of Thailand and Cambodia, The Guardian reported.
The two countries have been arguing over the 1,000-year-old Hindu Preah Vihear temple in that region, and the area is currently the subject of a U.N. International Court of Justice investigation, the Reporter said.
"The film presents some information on incidents that are still being deliberated by the Thai court and that have not yet been officially concluded," a statement from the minister of culture reads.
It is not clear whether the statement is referring to the land dispute or the 2011 protests, The Guardian reported.
Numbenchapol said he was disappointed by the decision and hopes to appeal to the National Film Board.