Chinese authorities are investigating after a viral video appeared to show a worker from Tsingtao urinating into a tank, believed to contain ingredients for its popular beer.
The clip has received tens of millions of views on social media.
The company said it alerted police immediately after the video came to its attention, adding that the batch of ingredients had been sealed.
Tsingtao is one of China's top beer producers and its biggest exporter.
In the clip which appeared online on Thursday, a worker, dressed in uniform with a helmet on, can be seen climbing over a high wall and into the container before urinating inside it.
The location tag of the clip reads "Tsingtao beer No.3 factory", local news outlet The Paper reported on Friday.
Business outlet "National Business Daily" later cited an internal source as saying both the person who took the video and the person appearing in it were not direct employees of the company.
In a statement published on Friday, the bureau of market supervision and administration of Pingdu City, where the factory is located, said they immediately set up a team and conducted an on-site investigation after spotting the video, and sealed the whole batch of ingredients that appeared in the clip.
It also added that the bureau would deal with the matter seriously once details are confirmed.
Tsingtao said on Friday that it "attached great importance" to the online video, and the police had started an investigation.
The OceanNewsUK has reached out to the company for comments.
Chinese social media has been shocked by the clip, as the brand is hugely well-known both at home and abroad.
"A piss that will ruin a lot of money, this worker has done some real damage here," a top-liked comment on X-like platform Weibo reads.
"Good thing I don't drink beer - but it's unimaginable if this brand is finished because of this," one user said.
"Is this the first time though?" another comment reads.
Shares in Tsingtao Brewery fell sharply when the Shanghai Stock Exchange opened on Monday morning but were trading broadly flat by the afternoon.
The Hong Kong market, where Tsingtao shares are also listed, was closed on Monday for the Chung Yeung Festival holiday.
