Bank of Japan (BOJ) data showed the nation's wholesale inflation accelerated again in June.
Price pressures continued to mount, as the government reduced energy subsidies intended to ease gas and electricity bills, according to Japan's broadcaster (NHK World).
The central bank's Producer Price Index last month rose 2.9 percent from a year earlier in a preliminary reading.
The index measures the prices companies charge each other for goods and services.
BOJ figures also showed that import prices rose 9.5 percent in yen terms from a year earlier on the back of the weak Japanese currency.
Businesses are expected to continue to pass on higher material costs in sales prices, raising the question how much that would affect consumer prices.