The Japanese government said Thursday it will step up inspections on fishery imports from South Korea.

Tokyo's Ministry of Health, Labor and Welfare has announced that it will expand monitoring inspections currently applied to 20 percent of South Korean halibut imports to 40 percent beginning next month.

The ministry said the measure is to prevent food poisoning, and said that fish from Korea is responsible for about ten cases of food poisoning in Japan each year.

But Japan's Sankei Shimbun newspaper said it's highly unusual for Tokyo to tighten inspections of fishery imports from a certain country.

The report suggested the move is a response to South Korea's years-long ban on fishery imports from eight Japanese prefectures stemming from the 2011 Fukushima nuclear disaster.

The World Trade Organization upheld the legality of Seoul's Japanese fishery product ban in a final decision issued earlier this year.

According to Kyodo News, Japan will also strengthen inspections on imported clams and sea urchins coming from not only South Korea but all countries from the current ten to a 20 percent ratio.