The Chinese embassy referred to the controversial role Britain played in supplying opium to China following the execution of British citizen Akmal Shaikh, according to a leading historian.

The official statement from the Chinese embassy said the "strong resentment" felt by the Chinese public to drug traffickers was in part based on "the bitter memory of history".

Jonathan Fenby, the author of The Penguin History of Modern China, said it was a reference to the two Opium Wars fought between China and Great Britain and its allies in the middle of the 19th century and the wider opium trade.

The trade in opium, often grown in India, boomed in China despite efforts to ban it with large amounts of the drugs being shipped into the country by British merchants.

Attempts by the Chinese government to disrupt the trade were met with force and Britain twice went to war to protect its stranglehold on the market and expand its reach into a country which had been closed off to western influence.

British merchants forced the Chinese to grant them access to Chinese ports and won the right for their citizens to be exempt from Chinese law.

Mr Fenby said: "The unequal treaties, as they became known, caused a great deal of resentment in late 19th century and 20th century China among Chinese nationalists.