Chinese catering company Yun Hai Yao has been convicted in Singapore after a mass food poisoning incident involving dozens of ByteDance employees.

On Wednesday, Yun Hai Yao's CEO Lu Zhitao appeared in Singapore's State Courts and pleaded guilty on behalf of the company to two charges: violating the Environmental Public Health (Food Hygiene) Regulations and the Sale of Food Act.

According to prosecutors, food supplied by Yun Hai Yao contained high levels of staphylococcus aureus, a bacteria known to cause vomiting, diarrhea and stomach cramps. Testing found 200,000 CFU/g of the pathogen in a dish of stir-fried diced chicken – 2,000 times the legal limit of 100 CFU/g under Singapore law.

The meal was served on July 30, 2024, to staff at the Raffles Quay office of ByteDance, a Chinese tech company that owns TikTok ( or Douyin in Chinese) among other popular platforms. Shortly after lunch, 60 employees reported severe symptoms and were rushed to hospital.

A joint statement issued by the Singapore Food Agency and Ministry of Health the next day revealed that a total of 130 individuals fell ill after eating food from Yun Hai Yao and another vendor, Putien.

Health inspectors later discovered over 10 live cockroaches under a plastic mat in the food storage area of Yun Hai Yao's Northpoint City outlet – a key piece of evidence in confirming the source of contamination.

The court also cited a report by the Singapore Food Science Centre, which concluded the bacteria found in Yun Hai Yao's dish was the primary cause of the outbreak.

The company now faces a potential fine of up to 5,000 Singapore dollars (US$3,700). Sentencing is scheduled for July 17.

Yun Hai Yao, known for Yunnan-style cuisine, was founded in 2014 and currently operates around 130 restaurants in China. It expanded internationally in 2019, opening its first overseas branch at Singapore's Changi Airport. As of August last year, the chain had five locations in the southeast Asian country.