After plastic popped up in McDonald's Chicken McNuggets sold in Japan, Cargill is extending all apologies.

That's because the suspect nuggets were supplied by Cargill's chicken processing operations in Thailand.

McDonald's is one of Minnetonka-based Cargill's biggest customers, and the agribusiness giant is one of the fast-food behemoth's largest suppliers.

A customer at a McDonald's in northern Japan found a piece of plastic about 1 ½ inches long in an order of McNuggets. Bloomberg News reported a second plastic-in-McNuggets incident at a McDonald's in Tokyo.

McDonald's apologized to its customers. Cargill apologized "for any concerns caused by this situation," the company said in a statement.

"Food quality is our top priority, and we take these matters very seriously. We are now taking every action we can in collaboration with McDonald's to determine the facts," Cargill said. "Based on the outcome of this investigation we will make any changes required to improve processes."

The McNugget issue comes at a bad time for McDonald's in Japan. It hasn't made money for a few years, and it's had other food safety incidents recently (that have nothing to do with Cargill).

Last summer, a human tooth surfaced in an order of Golden Arches french fries. A Japanese child was injured last month after consuming a chocolate sundae with a piece of plastic in it.