Around 20 percent of the 21 million tons of oil exported to Belarus in 2009 was used for domestic consumption with the rest exported after passing through Belarusian refineries.
Andrei Yevdochenko, the country's deputy foreign minister, called for an end to duties on Russian oil starting in January, Russia's state-run news agency RIA Novosti reports.
"There are duties inside the customs union that contradicts the norms and principles of international trade," he complained.
Minsk in July introduced a 12.7 percent rate hike for the pumping of Russian oil through the country. The tariff is roughly $1.60 for every ton of crude oil transported around 60 miles through Belarus. The previous tariff was $1.42.
An economic court for the Commonwealth of Independent States in September called on both sides to settle their differences over oil taxes within a month. Belarusian President Alexander Lukashenko said he was keen to find alternatives to Russian energy supplies, however.