Reliance Industries, operator of the world’s biggest oil refining complex, has ordered at least 15 million barrels of Russian oil since Russia invaded Ukraine in February, trade sources said.

Reliance has bought an average 5 million barrels a month for the June quarter, the sources said.

Reliance did not immediately respond to a Reuters’ email seeking comment.

Before the Ukraine war, Indian refiners, including Reliance, rarely bought Russian oil owing to high freight costs.

However, Western sanctions against Russia since its Ukraine invasion, which Moscow calls a “special operation”, have prompted many oil importers to shun trade with Moscow, depressing its crude prices to record discount levels.

Indian refiners have snapped up the cheap barrels as India, the world’s third-biggest oil importer and consumer, is hit hard by high oil prices. India imports about 85 per cent of its 5 million barrels per day oil needs.

While New Delhi has called for an immediate ceasefire in Ukraine, it has not explicitly condemned Moscow's actions. India has also abstained from voting on multiple United Nations resolutions on the invasion.

Refinitiv’s tanker flow data shows a supply of about 8 million barrels of Russian oil, mainly Urals, at the Reliance-operated Sikka port in western India, for arrival between April 5 and May 9.

Most of these barrels are supplied by Russian trader Litasco, the Refinitiv data shows. Traders said Reliance is buying Russian oil on delivered basis.

Reliance is scheduled to receive its first parcel of Russia's ESPO oil in early May, the Refinitiv data shows. This grade is mostly supplied to China.

Reliance operates two refineries at the Jamnagar complex in western India that can process about 1.4 million barrels per day (bpd) of oil daily.