Americans love to buy items that are made in the USA, but can consumers always trust the labels are accurate?

One watchdog group says retailing giant Walmart (WMT) has a number of mistakes on its website, with items listed as "Made in the USA" that actually have packages indicating they were "Made in China." A Walmart spokesman told CBS MoneyWatch that "a small percentage of items" were mislabeled because of coding errors. The problem arose because some items that had been manufactured in foreign countries are now being made in the U.S., but not all of the labeling had been updated, the company said.

The accusation comes amid a $250 billion push from Walmart to buy products that support American jobs. That business effort is supported by an economic incentive, given that eight out of 10 American consumers told Consumer Reports recently that they'd rather buy a U.S.-made product than a foreign one.

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Yet with manufacturing becoming more complicated, it's not always clear what products are 100 percent American. Fakes also make it on the market, Consumer Reports noted.

The watchdog group, Truth in Advertising, said in a letter sent to Walmart on Monday that it had found more than 100 labeling errors on its website.

"False made in USA labeling on Walmart's website has misled consumers looking to purchase American-made products,'' Truth in Advertising executive director Bonnie Patten said in a statement. "The largest retailer in the world should have made sure its American-made claims were accurate before affixing made in USA labels on the products. Until Walmart cleans up this mess, consumers cannot rely on Walmart with regard to where a product is really made when shopping on the site."

Patten added in an email to CBS MoneyWatch: "It is disingenuous for Walmart to attempt to deflect blame by saying that it simply jumped the gun on placing Made in the USA labels on certain products that were transferring operations to the U.S. Our investigation revealed dozens of examples where Walmart simply got it wrong and in so doing violated the federal law on Made in USA labeling."

The issues, according to Truth in Advertising, include products with USA labels that misrepresent the origin of the products, USA labels that conflict with the information contained on the product specifications and USA labels that don't clearly state that only a percentage of the product is made in the U.S.

"[Our] findings make it clear that Walmart's website is mired in USA labeling errors," wrote legal director Laura Smith in the letter. "Walmart's use of its USA labels and specifications is false and deceptive, and therefore in violation of the Federal Trade Commission's standards for making U.S.-origin claims."

Walmart said it was confident in the "overall integrity of the information on our website." It added, "We ... are seeing some great results. For example, in Chicago, Ferrara Candy has re-shored some of its production from Mexico, creating more than 100 jobs in the community, and Korona Candles, which re-shored tea light production from Poland, is creating more than 150 jobs in the Dublin, Virginia, area."

The retailer said it's currently removing its "Made in the U.S." badges from its website because of a search-engine glitch (the products weren't showing up in search results) but is working on adding that and other badges, such as products that are labeled as supporting women-owned business, back on the site.

One way to figure out if a product is really "Made in the USA" is to check its "country of origin" mark, which is required by Customs and Border Protections of all imported goods, according to Consumer Reports. Such a mark, which is usually found on a sticker, isn't required of items made in the U.S. If you suspect an improperly labeled item, you can file a complaint at FTC.gov or call 877-FTC-HELP.