A small business in China has been devastated by the potential loss of 30 million yuan (US$4.2 million) after an employee accidentally labelled some of its washing machines with the wrong prices, triggering a buying spree.

Little Swan Dongshan Franchise Shop, which also has a brick-and-mortar outlet in Jixi county, Anhui province in southeast China, apologised and asked customers to withdraw their orders, Red Star News reported.

More than 40,000 orders were placed with its online shop in about 20 minutes on the evening of August 28.

Little Swan is a leading domestic washing machine brand and customers had spotted the extremely low prices at the franchise shop.

The shop said it was an error made by one of its workers who misunderstood the preferential rules of the shopping website Tmall, operated by Alibaba Group, owner of the South China Morning Post.