South Korea's prices of imported farm goods marked a negative growth for four straight months in June due to continued fall in agricultural product prices, customs data showed Wednesday.

The import price index for agricultural, livestock and fishery products reached 122.2 points in June, down 3.1 percent from a year earlier, according to the Korea Customs Service (KCS). From a month before, the index gained 4.3 percent.

The index logged the on-year decline for four months in a row after posting its first on-year drop in 17 months in March.

Prices for imported agricultural products retreated 3.5 percent in June from a year before. Prices for seasoning vegetable such as red pepper, garlic and onions showed an overall downward trend last month, while prices for cereals and nuts mostly showed upward trend.

Imported livestock product prices dipped 0.4 percent on-year in June, down from a 3.5 percent rise tallied in May. Prices for chicken meat and pork jumped 45.6 percent and 10.6 percent each, but beef prices were down 2.7 percent last month.

Meanwhile, prices for fishery products advanced 0.3 percent on- year in June, down from a 2.5 percent advance in the previous month. Prices of scallop, pollack and webfoot octopus jumped 37.7 percent, 32 percent and 20 percent each, but those of hairtail and small octopus declined 5.1 percent and 16.6 percent each.