Customers are suing Whole Foods Market for “vastly understating” the amount of sugar in its store-brand yogurt.

A class-action lawsuit filed Friday in Manhattan federal court cites six tests by Consumer Reports in a July report on the supermarket chain’s Whole Foods 365 Everyday Value Plain Greek Yogurt, revealing it actually contains 11.4 grams of sugar per 170-gram serving instead of the 2 grams listed on the label.

“Defendant’s act in vastly understating the sugar content . . . is not harmless trivia,” the suit says. “For many members of the class, sugar content is an important component of their diet.”

The suit, involving about 100 plaintiffs, alleges that competing Greek yogurts typically contain 5 to 10 grams of sugar and that no yogurt on the market can claim 2 grams of sugar because even unsweetened yogurt naturally contains more than 2 grams of sugar lactose.

The sugar content in Whole Foods’ yogurt is nearly as high as an ice-cream sandwich, which contains 13 grams, the suit claims.

The suit cites the chain’s Web site, which claims a registered dietician regularly reviews each nutrition label of Whole Foods products for accuracy.

“Unless this statement on the defendant’s Web site is false, then Whole Foods Market was fully aware of the contents of its store-brand Greek yogurt and of the fact that the yogurt’s actual sugar content was dramatically higher than what is stated on the label,” the suit says.

Whole Foods says it has removed the yogurt and is investigating the publication’s report.

“We strive to only provide the highest quality products with accurate product labeling under our 365 Everyday Value line. This product was tested by a reputable third-party lab using FDA-approved testing methodology to determine the labeling,” said spokesman Michael Sinatra.

“While we continue to investigate Consumer Reports claims, we have removed our 365 Everyday Value Nonfat Plain Greek Yogurt from store shelves.”

The suit alleges that Whole Foods knowingly falsified the yogurt labels.

“Defendant made it seem as if the higher price of this product was justified because it had only 2 grams of sugar per serving, which — if true — would have made it the Greek yogurt with lowest sugar content on the market,” the suit says.

It seeks $5 million in damages.