The chief of BP's Russian oil venture was yesterday summoned for questioning by the interior ministry as part of a criminal investigation into possible large-scale tax evasion.

The move adds to the pressure on BP amid a battle for control of TNK-BP between its British and Russian shareholders. Tony Hayward, BP's chief executive, is due in Moscow today for talks with the company's Russian shareholders and government officials aimed at resolving a stand-off that is threatening to paralyse the company's decision-making.