But it has indicted three officials from a McDonald's burger patty supplier for violating hygiene control and food safety regulations. Prosecutors uncovered their possible negligence in the course of the investigation.

Prosecutors launched a probe into the fast food chain after a local consumer filed a complaint last July accusing McDonald's of being responsible for her 5-year-old daughter's incurable kidney disease.

The mother filed the complaint last July claiming her child was diagnosed with hemolytic uremic syndrome after eating one of its burgers served with an undercooked patty. The girl has to receive a dialysis for the rest of her life.

As a series of similar complaints followed, the prosecution dug into the allegations by questioning related persons and consulting medical professionals regarding a possible correlation between HUS and undercooked meat.

The prosecution said it found no hard evidence to back up the suspicions that McDonald's burger patties were contaminated with a pathogenic microorganism. It said it was thus difficult to establish that an undercooked patty was the cause of the symptoms related to HUS, or the diarrhea and stomach pain other consumers claim to have suffered. (Yonhap)