Canada's food safety regulator has concluded Joriki, the co-manufacturer of plant-based milks sold by Danone and Walmart in the country, did not follow necessary protocols to prevent listeria contamination.

In its conclusion to the probe, the Canadian Food Inspection Agency (CFIA) said Joriki "did not properly implement environmental swabbing and finished product testing".

The watchdog was unable to find the main source of contamination, but noted this was "not uncommon" for pasteurised products, and that "cross-contamination could have occurred after processing".

An investigation into a potential listeria outbreak began in June, when the government agency Public Health Ontario notified the CFIA of a listeriosis illness outbreak in the province and evidence of listeria monocytogenes found in a sample of Silk unsweetened coconut milk.

In July, the CFIA then confirmed cases of listeria contamination in July in plant-based milks made by Danone's Silk and Walmart's privte-label brand Great Value.

It issued a recall on 15 Silk items, including almond, coconut and oat-based milks, plus three Great Value almond-based milks.

The following month, the regulator traced the outbreak to "dedicated production line" at a facility in Pickering, Ontario, run by third party manufacturer Joriki.

Two deaths were reported in July, while ten people were infected. In its conclusion to the investigation, the CFIA said the outbreak killed a total of three people.

As a result of the latest investigation, production at the Joriki facility had been "fully halted", while "significant cleanup and renovations" takes place.

"Manufacturing will not resume until all necessary safety measures are in place, and until we are confident that the risk of contamination has been eliminated", the regulator said.

It added that it plans to continue visiting and surveilling the site to ensure necessary "corrective actions" take place.

The CFIA said it did not carry out a licence investigation into the Pickering facility before the listeria outbreak, as the site was not deemed to be a high-risk environment, based on the regulator's 2021 risk assessment.

It had visited the Pickering facility on several occasions between 2018-2019 and 2023-2024, following several consumer complaints linked to potential allergens, off-taste and mould in products. Joriki was said to have taken "All necessary action" to resolve these issues.