Mikhail Khodorkovsky, former head of the Yukos oil company and Kremlin critic, was placed on an international wanted list and an arrest warrant in absentia was issued against him for being involved in the 1998 killing of Vladimir Petukhov, a Siberian mayor, a police spokesman said Wednesday. Earlier in December, Khodorkovsky had been charged in absentia for organizing the murder of Petukhov.

"After considering the petition of the Russian Investigative Committee’s department on investigating particularly important cases, the court has chosen detention as the measure of restraint against Mikhail Khodorkovsky. Mikhail Khodorkovsky has been put on an international wanted list," Russian Investigative Committee (IC) spokesman Vladimir Markin said, according to Russian Tass news agency.

Khodorkovsky not only faces Petukhov’s murder charges but has also been charged for the attempted murder of Nefteyugansk mayor’s companion Vyacheslav Kokoshkin as well as attempted murder of the executive director of the East Petroleum Handelsges company, Vyacheslav Rybin, according to reports.

Khodorkovsky, who was once considered one of the richest men in Russia, was arrested in 2003 and charged with fraud and tax evasion in what has been previously referred to as an inquiry orchestrated by Kremlin. In May 2005, he was sentenced to nine years in jail and, in December 2010, while he was serving the sentence, his jail time was extended till 2014. He was pardoned by Putin in 2013, following which he moved to Switzerland after getting a three-month Schengen visa, and later a residence permit.

On Tuesday, Russian investigators searched the offices and apartments of employees of Khodorkovsky's Open Russia group. However, investigators said the operation was a part of the 2003 embezzlement case at Yukos.