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...