Rosneft chief Sergei Bogdanchikov failed to testify at the second trial of Mikhail Khodorkovsky on Thursday because he was attending a government meeting on the bombed Baksan hydropower station.
Bogdanchikov gave no formal explanation for his absence, but a source close to him said Deputy Prime Minister Igor Sechin ordered Bogdanchikov late Wednesday to attend a government meeting in Nalchik the next day, Vedomosti reported.
Media reports have claimed that Sechin masterminded Khodorkovsky's first trial, which landed the businessman in jail for eight years and left him without his oil company, Yukos, most of which was sold to Rosneft.
Dmitry Peskov, a spokesman for Prime Minister Vladimir Putin, confirmed that Bogdanchikov had attended Thursday's meeting.
Unidentified attackers killed two guards and blew up two of the three generators at the Baksan station in Kabardino-Balkaria early Wednesday.
Rosneft has pledged to supply the station with fuel, Vedomosti reported.