Mouldy bread, rotting meat and seafood were discovered at the Chengdu No 7 Experimental High School, the BBC reported on Thursday.
The scandal first emerged when a small group of parents were invited on Monday to attend a tree planting event at the private high school in Chengdu, the capital city of Sichuan province.
While at the school, a group of parents discovered mouldy bread, rotting meat and seafood items in the canteen kitchen.
“(The items looked like they had) been in a freezer for years, (it looked) like zombie meat,” a parent told the BBC.
“I smelled the pork, it was stinky. (There was) ginger, which looked disgusting too.”
According to the parent, the private school costs 39,000 yuan ($5,800) a year – about 20 times the amount a public school would cost.
The group of parents shared the pictures of the rotten items on social media.
The Chengdu school later released an apology, and said it would stop taking food from its current supplier.
The school is one of the most prestigious in China and had in the past been named among the country’s “Top 10 outstanding private schools”.
It said that those responsible would be dealt with by the law, saying it was “embarrassed” by the incident and that it would not happen again.
Last year, an international school in Shanghai was found to have served expired food to its students.