There are countless studies that tout the heart-healthy benefits of olive oil. With high levels of monounsaturated fats, the premium stuff—extra-virgin olive oil—can help lower levels of bad cholesterol in your blood (the kind that causes heart attacks and strokes), is reported to have skin beautifying abilities, and might even help you keep off the pounds.

…That is, if what you are using is actually what you think it is. Turns out, most EVOO sold in the United States doesn’t pass international standards—and might just be a mixture of other low-quality oils disguised as the real stuff.

According to a 2011 study out of University of California, Davis, close to 70 percent oils sold in the United States as “extra-virgin” failed the International Olive Council (IOC) qualifying standards for the label. Working with the Australian Oils Research Laboratory, researchers tested 186 samples, finding that the majority had either spoiled after being exposed to high temperatures, had been combined with cheap refined oil, or had been made from damaged olives.

In 2015 the National Consumers League followed up on the study, testing 11 products taken from supermarket shelves. More than half were found lacking, prompting NCL to file a complaint with the US Food and Drug Administration. Still, little has been done to regulate the mislabeled oil. Even though the USDA set standards for the industry in 2010, they are rarely enforced.

This week, 60 Minutes’ producer Guy Campanile did an exposé on the corrupt, Mafia-run, $16-billion Italian olive oil industry that mislabels products sold on supermarket shelves:

The most common type of fraud, Campanile explains, is mixing Italian extra-virgin with lower quality olive oils from North Africa and around the Mediterranean. In other cases, a bottle labeled “extra-virgin olive oil” may not be olive oil at all, just a seed oil like sunflower made to look and smell like olive oil with a few drops of chlorophyll and beta-carotene. “Olive oil fraud has gone on for the better part of four millennia,” Campanile says. “The difference now is that the food supply chain is so vast, so global, and so lucrative that it’s easy for the bad guys to either introduce adulterated olive oils or mix in lower quality olive oils with extra-virgin olive oil.”

The problem has been ongoing for years. In 2007, investigative journalist Tom Mueller broke the story in The New Yorker, exposing the nefarious practices used by olive oil producers and has since written a book, Extra Virginity: The Sublime and Scandalous World of Olive Oil.

On his blog this week, Mueller reports that Italian authorities have begun to crack down. In November, they launched an investigation into seven of the biggest brands—Antica Badia, Bertolli, Carapelli, Coricelli, Primadonna, Santa Sabina, and Sasso—believed to fraudulently labeling their products, and just last month raided production facilities:

A hundred military police officers in Puglia, acting on orders from anti-mafia investigators, executed search and seizure warrants at olive oil companies that revealed the existence of 7,000 tons of dubious oil. Though marked as “100% Italian,” prosecutors allege that much of the oil was imported from Syria, Turkey, Tunisia and Morocco…Investigators are still scrutinizing these 7,000 tons of oil, much of which appears to have been sold already in Italy, the USA and Japan; insiders say that the oil’s allegedly false provenance may not the only thing wrong with it.

With so much bad oil still being sold in supermarkets, Mueller and Consumer Reports have created lists of olive oils you can trust. Food Renegade recommends that it’s best to buy local.

Still, the issue is long from being solved—and points to the much bigger problems that come when food regulation is lacking.

“The battle now being fought in Italy over olive oil is part of a larger world war over food authenticity,” Mueller writes. “At stake is every consumer’s right to know the basics of what they eat: where your food comes from, who made it, what’s in it.”