"We will do this (tax return) if there is such a request," Alexei Sazanov, head of the finance ministry's tax department, told reporters.

Last week, Russia agreed to take back around 1 million tonnes of tainted oil stuck in Belarus.

Sazanov said he was not aware how situation with tainted oil stuck further down the Druzhba pipeline in Poland and Germany will be resolved, adding if it remained in these two countries and is not shipped back then no export tax return will be made.