A McDonald's?restaurant in Beijing has been found selling food that, under the rules, should have been thrown away.

Staff were also seen changing expiry dates and, in one case, putting back beef that had fallen on the ground, China Central Television reported yesterday.

The workers' violations were captured by undercover reporters and broadcast nationwide yesterday, China's Consumer Rights Day.

In video footage, staff at the McDonald's restaurant in the capital's central Sanlitun area were seen resetting clocks on ovens when they sounded an alarm that the food inside should be thrown away.

By resetting the clocks, the food could be reheated over and over again until sold, the program said.

At lunchtime on March 1, workers put a plate of fried chicken wings into the ovens where they should only have been kept for 30 minutes. But two hours later the wings had still not been thrown away and were still available to be sold.

Cheese pieces are required by restaurant rules to be discarded two hours after they are exposed to the air. But in the video, cheese sat on dishes for more than four hours, from 1:10am to 5:45am, to be then used in breakfast burgers.

Staff could also be seen writing expiry dates on packs and changing dates. The time on a batch of dessert pies which had to be sold before 10:20pm or thrown away was changed to 11:20pm, the video showed.

"According to regulation, the expired pies should be thrown away, but no branch restaurants would follow the rules and (the supervisors) are turning a blind eye," said a worker. "Regulations? They are made by human beings."

In another scene, raw beef fell on the ground but a worker simply picked it up and put it back.

"It's fine, it's not you who will eat them," said the worker. "The bacteria will all die when the beef is fried and no one will have any health problems after eating it."

Another worker said they broke the rules because everything that wasn't sold would add to costs and affect their bonuses. "Only when you gain profits, you can share the bonus," the worker said.

McDonald's China issued a statement saying the company would investigate, according to 163.com. It told the website that the "incident only occurred at the Sanlitun restaurant."

However, many microbloggers said they had seen similar violations in other branches.

Also on the program, several subsidiaries of China Telecom, including the carrier's Shanghai branch, profited from helping ad companies send spam messages, CCTV said.

Billions of messages were sent to mobile phone users through a special service offered by China Telecom, which allows ad companies to bypass other carriers' spam filters, it claimed.

Such practices were found in China Telecom subsidiaries in the cities of Shanghai, Dongguan, Guangzhou and Suizhou.

"China Telecom set no limit to how much spam these companies sent as long as they can pay up," CCTV quoted a insider as saying. "The ad companies will send at least 100 million messages a month."

In a statement, China Telecom said it had always opposed spam messaging and it would launch an investigation.

CCTV also found a Carrefour supermarket in Zhengzhou, capital of Henan Province, dividing chicken into two groups and selling it at different prices.

And former staff from China Merchants Bank were caught selling card holders' information to thieves, who could then steal money from the cards.