(Yicai) Oct. 23 -- Tsingtao Brewery, one of China’s biggest beer makers, said the police have begun an investigation after a video that appears to shows a factory worker urinating in a malt container went viral on social media.

All batches of malt involved in the alleged incident have been sealed, the Qingdao-based company said today, adding that its production and operations are normal.

After tumbling by as much as 7.5 percent in Shanghai this morning, the 120-year-old brewer’s shares [SHA: 600600] closed down 0.4 percent at CNY80.79 (USD11.04) each.

The video clip that began circulating online on Oct. 19 shows a man in a work uniform climbing into a large container of malt and then peeing inside. Some media reports said the warehouse in the video is at Tsingtao’s third plant in Qingdao, which has an annual production capacity of 1.2 million kiloliters of beer.

A source told Yicai that the video does not show a raw materials container belonging to Tsingtao, but rather a shipping container at a logistics contractor, and the man is not a Tsingtao employee, but a loader hired by a third-party labor supplier.

Tsingtao, which has 60 breweries in China, is best known for its flagship product, Tsingtao Beer, which is a pale lager and one of the most popular beer brands in the country. It is also exported around the world.

Tsingtao’s first-half net profit jumped 20 percent to CNY3.4 billion (USD464.7 million) from a year earlier on a 12 percent increase in revenue to CNY21.6 billion (USD3 billion). The firm sold 5 million kl of beer in the six months ended June 30, a 6.5 percent gain from the same period of last year.

Editors: Dou Shicong, Futura Costaglione