In its latest report, the METI announced that the Eastern Asian country has imported 190,924 barrels per day (bpd) of Iranian oil in May 2015, showing a 5 percent increase, compared to the same month last year.
According to a Reuters report on Tuesday, Asian imports of Iranian crude rose to the highest level this year in May.
Imports by Iran's four biggest buyers - China, India, Japan and South Korea - totaled 1.2 million bpd last month, down 1.9 percent from a year ago and the highest since 1.21 million bpd in December, government and tanker-tracking data showed.
India's imports of Iranian crude oil rose 66 percent from a year earlier to their highest level since March 2014. Two months earlier India had imported no oil from Iran for the first time in at least a decade.