The U.S. Food and Drug Administration said on Wednesday it is investigating Greek yogurt maker Chobani’s handling of a mold problem with its product after the company asked some retailers last week to remove yogurt cups from store shelves.

Consumers had complained to Chobani over social media about off-tasting yogurt with bloated containers. Some reported gastrointestinal distress; others deplored the characteristically thick Greek yogurt’s “runny” consistency.

The company did not issue a recall notice over the problem, the FDA told Reuters, but instead the company contacted stores directly.

Chobani did not provide a response after multiple emails and calls for comment and its website was down on Wednesday evening, making it impossible to access prior statements on the subject.

On Tuesday, Chobani told Food Navigator, an industry publication, that it had “investigated the cause of the (swelling/bloating) and have identified a type of mold commonly found in the dairy environment.”

The private company said the problem had affected less than 5 percent of its production and was limited to yogurt cups produced at Chobani’s Idaho plant. The company also has a plant in New York and one in Australia.

Also on Tuesday, Chobani said in a Facebook comment that cups with the code 16-012 and expiration dates between 9/11/2013 and 10/7/2013 would be replaced.

On Friday, it posted on its Facebook page that it was “in the process of voluntarily removing and replacing some products from store shelves that did not meet our rigid quality standards.”

Chobani’s handling of its yogurt recall is unusual, according to Tamara Ward, a spokeswoman for the FDA.

Ward said the FDA is in discussions with the company to assess the nature of the problem, the level of risk to the public, whether the issue has been contained, and whether Chobani is doing enough to communicate any risk to the public.

So far the company has not issued a formal recall notice since it does not believe there is a safety risk, Ward said, though the product appears to be going bad early.

Ward said that the FDA “would expect” to be told of any potential safety risk with a product. The agency does not plan itself to issue a recall but is currently examining the company’s communications and would oversee any recall notice issued by Chobani.

Euromonitor, a sales tracking firm, ranks Chobani, a private company, second-best selling brand in the U.S. Greek-style yogurt market, after Yoplait.

Greek-style yogurt, which is thicker, creamier and often higher in protein that other types of yogurt, now makes up more than 40 percent of the U.S. yogurt market, Reuters has reported.

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By Atossa Araxia Abrahamian and Toni Clarke