Filming was delayed when actual squatters took up residence in the Chinese squatter village set. After their removal, filming resumed and the Chinese squatters stayed to watch. When the village is torched, crying and wailing can be heard. This wasn't from the Malay extras but from the real squatters who just lost their new home.
During a forced break in filming due to heavy rains, a Malay Bomoh, or shaman, was hired to predict when the rains would cease. His prediction was spot on and filming resumed.
Because the UK government deemed the script to be prejudicial to British interests, it refused to cooperate. Therefore, all British troops were portrayed by Australian troops who were, at the time, running operations along the Malaysian-Thai border.
The character of Ferris is partially based on John Davis, a former SOE officer who worked with Chin Peng during the war. In 1955 he was sent by the government to bring Chin Peng out of the jungle and escort him to Baling for a peace conference.
Michael Keon, author of "The Durian Tree" on which this film is based, was a journalist working as Australian press attaché in China during the Communist revolution. During that time it was rumored that he operated as a spy for Western intelligence.