Austrian police have discovered rat poison in an empty jar of baby food during an investigation, after HiPP recalled a product line over suspected tampering. The company stated on Sunday that its production process was not at fault, AFP reports.

The German branch of HiPP announced a recall of products sold in SPAR supermarkets in Austria late Friday, citing the possibility that a “hazardous substance” had been added to the “carrots with potatoes” puree as a result of deliberate adulteration.

As part of the ongoing investigation, police have seized jars in Austria as well as in the Czech Republic and Slovakia, according to a statement from authorities in Austria’s eastern province of Burgenland released late Saturday.

“A sample of the seized product was tested Saturday afternoon and returned a positive result for rat poison,” officials said.

On Sunday, HiPP stated that its “production processes, quality, and controls are fully intact,” and that the incident is “in no way related to product quality or manufacturing.”

Austria’s food safety agency said Saturday that the rat poison may have been introduced as part of an extortion scheme.

Consumers have been advised not to consume the product, which can be identified by a white label with a red circle on the bottom of the jar, and instead return it to the store where it was purchased. Czech police also issued a warning to consumers on Sunday.

Since December, several manufacturers, including European giants such as Nestlé, Danone, and Lactalis, have recalled infant formula products from more than 60 countries that may have been contaminated with the toxin cereulide.

According to French authorities, several infants who consumed powdered milk containing cereulide—which can cause nausea, vomiting, and diarrhea—have died.

In March, French prosecutors stated that the death of one child in January “appears not to be linked” to the consumption of contaminated formula.