Ananova:

Police have raided the headquarters of Japan's largest dairy products maker for evidence that it supplied bacteria-tainted milk that caused a massive food poisoning outbreak.

Investigators are searching Tokyo-based Snow Brand Milk Products on suspicion of professional negligence, as well as Snow Brand's regional main office in the western city of Osaka. No arrests have been made.

Most of the 14,800 people made ill in the June food poisoning outbreak live in Osaka, about 254 miles west of Tokyo.

The Snow Brand case and a chain of other recent contaminations of food with bugs, broken pieces of plastic and other objects, have triggered a national food scare and loss of public trust in Japan's food industry.

The Snow Brand cases were initially blamed on staph bacteria in a production-line valve for low-fat milk at the Osaka plant, which was closed down indefinitely.

Later, local government and company officials said it may have been caused by staph bacteria toxins in powdered milk produced at another Snow Brand factory on the northern island of Hokkaido, but used at the Osaka plant to make milk products.

The powdered milk was not sold separately on the market.

Police suspect Snow Brand failed to take necessary sanitary measures at its plants resulting in the food poisoning.

In a statement Snow Brand said: "We apologise for the trouble we have caused to so many people. We will co-operate in the investigation in any way we can."

Inspections conducted by Health and Welfare Ministry officials found that the Snow Brand had also recycled milk returned from stores, including some with expired dates for freshness.