It’s not exactly breaking news that large-scale food producers use deceptive marketing and shady cutting agents to sell consumers foodstuffs that aren’t quite what they claim to be; olive oil is often mixed with less expensive oils, like canola; wood chips have been found in grated parmesan cheese; and there’s that chilling urban legend about calamari, propagated by a hugely popular episode of “This American Life” in 2013, that claims that pig rectum is used as an imitation squid product by restaurants everywhere.

Now, it’s possible that garlic powder is the next fraudulent food on the market. Spices in general are likely to be tampered with, because their pulverized nature makes it easy to obscure ingredients: but Professor Christopher Elliot, director of the Institute for Global Food Security at Queen’s University Belfast, claims that recent interruptions in the crop growth of garlic makes it particularly likely that garlic powder is being diluted with some pretty sketchy stuff.

Elliot says that the continued rise in garlic sales, contrasted with a cold weather stretch in China (where seventy-five percent of the world’s garlic is grown) that interfered with the crop, make it highly unlikely that purveyors could continue to distribute garlic powder at the rate they previously had. He speculates that garlic powder is being cut with chalk or talcum powder to keep up with high demands. However, his hunch has yet to be proven unequivocally.

That said, this isn’t the first time that Chinese garlic has come under intense scrutiny for questionable health practices. Accusations have been made that raw human sewage was used to fertilize the crop–though, once again, these claims have been largely unproven.

Elliot has a good track record when it comes to seeking out fake food: his research was crucial to recent discoveries about dried oregano–which is apparently often beefed up with additional leaves, like olive and sumac. Last April, Elliot told the Sydney Morning Herald that the oregano issue could be indicative of other fraudulent practices, stating; “Clearly we have identified a major problem and it may well reflect issues with other herbs and spices.”

Fake food is a prolific problem. Operation Option IV (an Interpol-Europol joint operation) seized over 2,500 tons of fraudulent food within the span of just about a month, from December 2014 to January 2015. The counterfeit products they collected ranged from cheeses, to dried fruits, to alcohol, to eggs. The scope of this problem is clearly quite large, and although there are those dedicated to unmasking the illicit food activities, there’s still a lot of work to be done.

The lesson here is just to be vigilant when it comes to the food that you buy. Look at labels, try to understand the ingredients and origins of your food, and most importantly, buy directly from the source when possible. Farmer’s Markets with local produce are really the best way to go if you want to avoid undeclared additives.