A former governor of the Luhansk Oblast, from 2010 until 2014 he was Party of Regions's faction leader in the Verkhovna Rada (Ukraine's parliament).

[6] Yefremov was again detained on 30 July 2016 on suspicion of violation of Ukraine's territorial integrity by helping to create the Luhansk People's Republic and misappropriation of property.

In 1973-78 he studied and graduated from the Voloshylovhrad Machine-building Institute (today the East Ukraine Volodymyr Dahl National University) as engineer-mechanic.

In 1987-91 he was on managerial positions at the Lenin Machine-building Plant, deputy chief of department, sectary of party committee.

From 2010 Yefremov heads the parliamentary faction of the Party of Regions changing on the post Viktor Yanukovych.

[18] Yefremov was also suspected of putting pressure on state coal company Luganskugol to make it conclude contracts with service providers controlled by him for excessive prices.

[6] Yefremov was again detained on 30 July 2016 at Boryspil International Airport (he was about to fly to Vienna) on suspicion of violation of Ukraine's territorial integrity by helping to create the Luhansk People's Republic and misappropriation of property.

"[8] According to the office of the Prosecutor General of Ukraine in October 2023 Yefremov had no preventive measure applied against him and was not on the wanted list.