As a national treasure, the secret skills of face-changing cannot be revealed just to anyone. [file photo]

Wang Daozheng, a 68-year-old professional of the changing-face performance, was shocked when he found a Japanese artist performing it in public in 2002.

"I refused US$50,000 from a Japanese artist when he approached me to learn the technique in the summer of 1987," recalled Wang. "However, one of our domestic Chuanju performers sold the skill to a Japanese artist for very little money."

Later, Wang frequently found foreign performers, in poor opera dresses, performing the same technique during his visits to South Korea, Singapore and Germany.

The current situation and future development of this unique skill are in great danger due to the illegal leak. Training in the art is even found on Internet ads for around 800 yuan (US$100).

"The changing-face performance can be seen everywhere, from night-clubs, bars and even massage centers in China," said Wang. "Most of these performers are too clumsy and the string connecting the two masks is usually exposed on their faces."

The State Ministry of Culture declared the changing-face performance of Chuanju Opera a level-two state secret in 1987. The performance is the only state secret pertaining to traditional opera.

Chuanju Opera, one of the oldest local operas, popular in Sichuan Province and some regions of Southwest China's Yunnan and Guizhou provinces, has built its own system of stylized movements.

Its special characteristics include immortals who have a third eye on their forehead that can open suddenly to show their magic power; quick changes of facial characteristics without makeup; and jumping through burning hoops.

Changing-face is the prime feature of the opera. Performers change masks very quickly, almost instantaneously with a quick wave of the hand or by turning around. Professionals can change around 15 masks during one performance.