China's crude oil imports from Iran were about 384,980 barrels per day in June, down 39 percent versus the same month a year ago, and down 31 percent from May, Chinese customs data showed on Monday.

For the first six months of the year, Chinese imports of Iranian crude were about 424,183 bpd, down 1.9 percent versus the same year-ago period, the data showed.

China's crude purchases from Tehran in the first half of last year fell nearly 21 percent from the same period in 2011 because of a contract dispute that slashed imports in the first quarter.