China has slashed its oil imports by about a quarter from prewar levels, resulting in more crude being available to the wider market and benchmark oil prices being capped near the $100-a-barrel level. According to industry executives, Chinese state-owned oil companies have been reselling some of their oil cargoes to European and Asian rivals, suggesting surpluses despite the supply shortage.

The shift has not only capped benchmark oil prices but also triggered a collapse in the premia that traders pay above them to secure physical crude.

Tanker-tracking data estimates that China is buying just 8.2 million barrels a day of crude from overseas, down from a prewar level of around 11.7 million.

The import drop might make sense if Chinese commercial inventories were falling sharply, or if Beijing had tapped its strategic petroleum reserves, but neither is happening.

The International Energy Agency estimates that Chinese oil demand slipped into a modest year-on-year contraction in both March and April, but this drop is not enough to explain why imports have fallen so much.

The court will resume hearing on the impact of China's reduced oil imports on the global market, and officials will provide further analysis on the reasons behind this decrease.