KFC has been exposed by CCTV that its ice cubes contain levels of bacteria far above the national limit.

Yum Brands Inc., the parent company for KFC, announced on Thursday that the ice cubes used by KFC in Beijing found to contain levels of bacteria far above the national limit were the result of an accident, following China Central Television's (CCTV) exposure, Southern Daily reports.

According to CCTV, ice cubes used by fast food giants including KFC, McDonald's and Guangzhou-based Kungfu at their Beijing branches were tested to contain bacteria at severe levels, and some were even dirtier than toilet bowl water.

Su Jingshi, the CEO of Yum! China said that KFC has strict sanitation regulations and equipment to produce ice cubes, as well as strict operation of its staff.

Su said that the ice cubes found to contain bacteria were in the Congwenmen outlet, which always passed sanitation tests in the past. After the exposure by CCTV, they carried out inspections and found nothing that did not pass test standards; Su said that this incident was a one-off accident.

Su emphasized that he would enhance disinfection procedures at the KFC stores.

Earlier, CCTV reporters sent ice cubes from the Chongwenmen outlets of KFC, McDonald's and Kungfu for lab tests. The KFC ice cubes contained levels of bacteria which were 20 times higher than the limit, and 13 times higher than water samples taken from toilet bowls.

The amount of bacterial colonies found at McDonald's and Kungfu ice cubes reached 120 CFU and 900 CFU (colony-forming units) per milliliter respectively, exceeding the national limit of 100 per milliliter.

The CFU level of Kungfu's ice cubes was six times higher than toilet water, CCTV reported.

The intake of food with excessive levels of colonies could lead to dysentery and diarrhea, said Ding Ke, an associate professor of food science and engineering of the Beijing University of Agriculture.