India is bound by UN sanctions, but "unilateral sanctions imposed by countries or group of countries shouldn't impact legitimate trade relations with Iran," Indian Foreign Minister S.M. Krishna Krishna told lawmakers in a written reply in the upper house of parliament.
He said New Delhi's crude oil imports from Tehran are guided by India's energy needs.
India has vaulted to the top of the list of Iran's oil customers, overtaking China, in a first-quarter buying surge despite the West's tighter sanctions against Tehran, data published by a leading industry consultant showed.
Direct imports to India from Iran were 433,000 barrels per day (bpd) in the first quarter, compared with 256,000 bpd to China, according to data compiled by Geneva's Petrologistics and seen by Reuters via an industry source.
The Indian import figure was up by around 23 percent from the 351,0000 bpd imported over the same period of 2011 and significantly above the its 2011 average of 326,000 bpd.
The Petrologistics figures, however, reinforce indications that India has stepped up imports.