The customer visited the Lotus Rama IV outlet in Bangkok earlier on Monday when he spotted some brown bits in his coffee, which on close inspection turned out to be cockroach legs.
He claimed, in the post, that at first he thought the glass was dirty but when he took the cup back to the counter the staff found more cockroach legs in the coffee.
"But when the employees poured another cup, it seemed that they found more cockroach legs in the coffee. I felt even more terrible. I expected McDonald's to have high operation standards and clean your equipment... but nothing! At least when they prepared a coffee for customers, they should have seen the contamination inside," he wrote.
The post, shared on Mcdonald's Thailand Facebook page on Tuesday, went viral with over 1,700 shares forcing the company to issue a statement two days later.
The fast food giant apologised for the incident and admitted that the coffee pot had roach legs.
In September, a customer from Gurugram found insects crawling out of packets of Domino's Pizza seasoning.
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