“The three PetroChina tankers are the first Chinese ships picking up crude in Venezuela since the Russians, via Rosneft Trading, stopped acting as a cover for China deliveries and pulled out of Venezuela in March,” said Russ Dallen, head of Miami-based Caracas Capital Markets.

The US imposed sanctions on Russian traders earlier this year, which Mr Dallen said were being used by Venezuela’s PDVSA as an intermediary and “a beard” to disguise sales to China.