TOKYO, June 20 (Xinhua) -- An analysis company in Japan on Monday said food manufacturers have been raising their prices as soaring costs for raw materials and oil have forced some companies to pass on the costs to consumers.

       Analysis company True Data Inc. said the average price of cooking oil in supermarkets nationwide soared 150 percent in May and that of mayonnaise leapt 30 percent.

       The firm noted that a number of other food staples had also seen their average price rise considerably in the recording period.

       Resource and import-reliant Japan has seen import prices soar due to the yen's recent weakness versus the U.S. dollar as a result of central banks' monetary tightening and concerns over economic growth.

       Local economists said that prices were likely to continue rising due to increasing demand, import costs continuing to balloon and the yen's continued weakness.