Figures released by Reuters show that New Delhi shipped in 215,500 bpd from Tehran in February, a rise of about 21 percent from last month and more than double the figure of about 111,000 bpd in the same month a year ago.
In February, Essar Oil was the biggest buyer of Iranian oil, shipping in 110,200 bpd, followed by about 69,500 bpd by Mangalore Refinery and Petrochemicals Ltd.
MRPL shipped in just one cargo of Iranian oil in February.
Indian Oil Corp, which rarely buys Iranian oil, received a cargo of oil equivalent to about 35,800 bpd.
A true reflection of the step-up in Indian purchases of Iranian oil will emerge from April, the new contract year, as in the last leg of a fiscal year most companies cut purchases to maintain low inventory ahead of annual results, Reuters said.
Reliance Industries Ltd, which halted supplies from Iran in 2010, is preparing to lift a million barrels each of condensate and oil next month, it added.