The secret performing technique of "Bianlian", or face-changing, in one of the oldest forms of Chinese opera - Sichuan Opera - has been revealed by some performers without authority allowance.
The disclosure has provoked intense disputes in China on keeping secret or publishing tricks in the sector of performing technique as the country's Cultural Heritage Day, on June 10, moves closer.
Some artists of Sichuan Opera have sold the trick to other parts of the country and even overseas, according to Wang Daozheng, a 68-year-old face-changing master in Sichuan.
Some cultural experts have called for the case to be investigated the secret-teller to be punished. Some others believe China should not consider the art a state secret.
"An art recognized by the world has the most powerful life force," Peng Denghuai, another Sichuan-based face-changing master, told Xinhua,
"We should let the technique go abroad and make it a renowned Chinese cultural attraction to a global audience," Peng said.
Sichuan Opera is distinguished by the face-changing technique.Performers change masks in quick succession with a wave of the hand or by turning around.
Professionals can change around some 10 masks in 20 seconds. In China, there are only 200 artists who are able to perform face-changing.
Hu Jixian, vice-director in charge of art affairs of Sichuan province, said face-changing is a rare art heritage in China, calling for better protection and development of the technique.
Since it is listed as a high-level secret of China, this case of disclosure is an individual one and we will take appropriate measures to deal with it," the official said.