China is quietly ramping up purchases of oil from Russia at bargain prices, according to shipping data and oil traders, filling the vacuum left by Western buyers backing away from business with Russia after its invasion of Ukraine in February.

The move by the world's biggest oil importer comes a month after it initially cut back on Russian supplies, for fear of appearing to openly support Moscow and potentially exposing its state oil giants to sanctions.

China's seaborne Russian oil imports will jump to a near-record 1.1 million barrels per day (bpd) in May, up from 750,000 bpd in the first quarter and 800,000 bpd in 2021, according to an estimate by Vortexa Analytics.