Popular hotpot chain Haidilao will have its outlets in Beijing inspected by food safety authorities following a sanitation scandal.

Two Haidilao branches in the Chinese capital were found to be operating in unhygienic conditions, news agency Xinhua reported on Sunday (Aug 27).

Videos taken by hidden cameras showed a rat-infested kitchen, a dishwasher caked with oily food residue and a worker attempting to fix a sewage clog with a food ladle.

The Beijing Food and and Drug Administration said the inspection will take place over two weeks, and target both the chain's outlets and food suppliers.

It will scrutinise Haidilao's business licenses, dishwashers, sanitation equipment and its measures to keep out pests.

Haidilao has been ordered to open its kitchens in a month, and report the new measures it has adopted.

Its sanitation ratings will be downgraded.

In a statement on Friday, Haidilao had apologised for the scandal and admitted that its management was at fault for the lapses.

It also promised to ensure that all its restaurants in China and abroad would be maintaining good sanitation standards.

Haidilao, which is known for its Sichuan-style hotpot and quality service, was started in 1994.

It has five outlets in Singapore - at Clarke Quay, 313@Somerset, IMM, VivoCity and Bedok Mall. There are reportedly plans to open a sixth at Plaza Singapura.

Singapore's National Environment Agency was not immediately able to comment at press time, while Haidilao Singapore could not be reached for comment.