South Korea's import prices dropped 3.5 percent last month from a month earlier due to a fall in crude oil and petroleum products, the central bank said Friday.

In local currency terms, import prices retreated 3.6 percent in June from a month before, down from a 1.9 percent on-month decline tallied in the previous month, according to the Bank of Korea (BOK) . From a year before, the prices fell 1.2 percent last month, the first on-year slide since March 2010.

The June figure logged the three straight month of on-month decline due to falling oil prices. Dubai crude, South Korea's benchmark, averaged 94.4 U.S. dollars a barrel in June, down 12.1 percent from a month earlier.

Import prices for raw materials decreased 6.7 percent on-month in June. Prices for mining products imported from overseas dropped 7.2 percent, with agricultural product prices falling 1.7 percent.

Intermediate goods prices retreated 1.9 percent in June from the previous month after posting a 0.7 percent decline in May. Petroleum product prices tumbled 14.8 percent amid lower oil prices, and prices for primary nonferrous metal products slid 2.1 percent.

Prices for capital goods gained 0.8 percent on-month in June, but consumer goods prices declined 1.4 percent over the same period.

In contract currency terms, import prices dropped 4.6 percent on-month in June. The South Korean currency depreciated 1 percent against the greenback last month.