The female customer, named Chen, exposed the incident in a Facebook group called Complaint Singapore on Dec. 4, reported news site AsiaOne.
In her post, Chen said that the meat, which was served to her in a burger she had bought at a McDonald’s outlet near Punggol Plaza in Singapore, was "cold and mushy." As she suspected that something was wrong with her dish, she opened the burger and found the patty was "not cooked."
As Chen contacted the restaurant manager, she was offered a replacement meal and a full refund, along with a promise to cover any medical expenses if she experienced food poisoning.
Still, Chen said she had developed a phobia following the incident.
It is reported that the Singapore Food Agency is now investigating the matter.
There have been other instances of undercooked McDonald’s products across Singapore in recent times.
According to Singaporean news site Mothership, a customer named Bryan Lee experienced diarrhea three times following having a meal at the brand’s Yishun Ring Road outlet, which consisted of a "pink and undercooked" hamburger patty.
Just days after Lee’s report, another customer had a similar issue with an undercooked hamburger patty from another outlet.
The fast food brand has responded to these incidents by apologizing to the affected customers and stated its commitment to the highest food safety standards.
It explained that the undercooked patties were the result of an error in the grill settings, and it had conducted a calibration exercise for all its restaurants to reinforce the need for all restaurant teams to strictly adhere to operational and cooking procedures.