The Canadian Food Inspection Agency says its investigation into an Ontario facility processing plant-based milk found it was not adhering to Health Canada’s policies on listeria prevention.

The facility is still shut down after a listeria outbreak last summer linked to the plant infected at least 20 people in Ontario, Quebec, Nova Scotia and Alberta and led to three deaths.

The federal agency says it visited the site six times and discovered the facility was not properly conducting environmental swabbing and finished-product testing for listeria. The probe was conducted after a national recall involving several Silk and Great Value plant-based milk products on July 8.

“That obviously was unacceptable,” Health Minister Mark Holland said Tuesday while providing an update on the outbreak.

The CFIA says Joriki, a third-party facility in Pickering, Ont., used by plant milk manufacturer Danone Canada, was not considered “high risk” prior to the contamination, based on the type of food it was producing and its manufacturing process.

A three-year survey completed by the CFIA in 2022 found plant-based milk alternatives to be “generally safe,” with no listeria found in the samples taken.

For that reason, the CFIA did not conduct a licence inspection prior to the investigation.

However, it did visit the plant in response to consumer complaints about allergens, an off-taste, and mould in 2018 and 2019, and then again in 2023 and 2024.

“All necessary action was taken by the establishment to resolve the complaints,” the CFIA says. The agency also noted its the first time plant-based beverages have been linked to listeria illness in Canada.

Holland called the outbreak a “tragedy.

Its imperative that we shut any deficiencies and understand what went wrong, he said.

The CFIA says this outbreak shows that “new risks” emerge as scientific evidence evolves, and that its inspector general has launched a review of the circumstances surrounding the recall to identify and eliminate similar risks from taking place at other facilities.

Production at the Joriki plant will remain paused until the CFIA is satisfied with renovations to the facility.

Representatives for Danone did not immediately provide a response to the CFIA update and attempts to reach Joriki through the facilitys website were not successful.