The export chief of Azerbaijan's state oil firm, SOCAR, Mukhtar Babayev, told the AFP news agency that SOCAR halted its deliveries to Russia on January 1.
Babayev said the oil would be used to fuel Azerbaijani power stations that formerly ran on Russian natural gas.
Azerbaijan has refused to pay Gazprom's new proposed price of about $230 per 1,000 cubic meters of gas. Gazprom is charging EU countries about $250 per 1,000 cubic meters.
Before January 1, Azerbaijan paid $110 per 1,000 cubic meters.
(with material from AFP, ITAR-TASS)