England's Tesco own-brand ice cream packages were taken off the shelves after police say they were deliberately spiked with painkillers.
Police with the major crime unit in North Yorkshire are leading the inquiry into the food contamination and had to issuing a recall back in November following the discovery of the pills by several customers.
A police spokesperson stated that the investigation has been challenging due to the many factors at play such as determining that it was a deliberate act and tracing those responsible while also informing the public about the hazard.
The spokesperson added that if it was thought to be accidental there would not have been the level of resources available.
R&R, the largest ice cream maker in Europe, manufactures the compromised Tesco brand ice cream and is now reviewing its manufacturing procedure in the wake of the recall given that it produces other leading brands of ice cream consumed throughout Europe.
According to Peter Pickthall, R&R's human resources director, the painkillers could not have been added by someone in the Tesco stores and had to be done by someone working in the factories.
He added, from the company's point of view, if there was evidence of anything where there was potential for a consumer to be injured in any it needed to be investigated.
The supermarket is taking four-packs of the ice cream off the shelves with sell-by dates up to and including July 2014.
"As a precautionary measure, we have issued a product recall," a Tesco spokesman revealed in a statement. "We are urgently investigating this incident with our supplier and ask customers to return this product to their local store."
A spokesman for the Food Standards Agency said: "If you have bought the product, do not eat it."