BEIJING - A rare 50-minute documentary funded by late Kuomintang (KMT) General Yang Hucheng in the 1930s was donated to the National Museum of China on Monday by Yang's offspring.

Yang was famously known for cooperating with General Zhang Xueliang to take then KMT leader Chiang Kai-shek hostage on Dec 12, 1936, demanding Chiang stop the civil war and unite with the Communist Party of China (CPC) in the war against Japanese aggression, which was later known as the Xi'an Incident.

In 1933, Yang sponsored a Shanghai-based film company to shoot the documentary about China's war-torn northwestern regions in a bid to boost his cause to end the civil war and unite the two parties.

"The footage serves as a key material for the study of General Yang's achievements and is also significant to deepen our understanding of local culture in China's northwest regions in the 1930s," said Lyu Zhangshen, head of the museum.

After the Xi'an Incident, Yang was imprisoned for 12 years and killed by KMT members in 1949 at the age of 56. The footage was preserved by his offspring.