Russia is entering its third year of war in Ukraine with an unprecedented amount of cash in government coffers, bolstered by a record $37 billion of crude oil sales to India last year, according to new analysis, which concludes that some of the crude was refined by India and then exported to the United States as oil products worth more than $1 billion.

This flow of payments, ultimately to Moscow’s benefit, comes from India increasing its purchases of Russian crude by over 13 times its pre-war amounts, according to the analysis by the Centre for Research on Energy and Clean Air (CREA), exclusively shared with CNN. It amounts to US strategic partner New Delhi stepping in to replace crude purchases by Western buyers, reduced by sanctions over Russia’s invasion of Ukraine, the analysis said.

While Russian crude sales to India are not subject to sanctions and are entirely legitimate, an examination of shipping routes by experts suggests this huge volume of shipments might involve the so-called “shadow fleet” of crude tankers, specially created by Moscow to try to disguise who it is trading with and how, and maximize the Kremlin’s profits.