A long-standing and widely-circulated rumour that the Forbidden City in Beijing uses 600,000 tonnes of pig’s blood each year to dispel evil has been debunked.

The liquid is actually used as a form of adhesive which is painted on the famous palace’s signature red walls and pillars, according to a recently published book.

The book Sitting under the Roof of the Forbidden City: Answering 50 Questions about the Forbidden City is wrote by Zhou Qian, a researcher at the palace for 20 years who is also an ancient architecture specialist, the Beijing Daily reported.

Zhou refutes some groundless rumours about the palace, including that of the pig’s blood.

“The mixture painted outside the wooden structure or wall is called di zhang ceng, which really does contain pig’s blood. However, pig’s blood is not adopted to drive away evil, but used as an adhesive,” said Zhou in his book.