Russia's top investigative body on Wednesday declared Mikhail Khodorkovsky as arrested in absentia, two years after the Kremlin critic and former oil tycoon was pardoned after serving 10 years in prison.

Investigators earlier this month accused the former billionaire of involvement in the 1998 murder of a Siberian mayor. On Tuesday, Russian officials searched the residences of several employees of his Open Russia foundation in connection with a probe into a privatization deal.

Khodorkovsky, 52, spent 10 years in prison on tax evasion and embezzlement charges widely seen as punishment for challenging President Vladimir Putin's power. His oil company, once Russia's largest, was dismantled and sold off to state-owned firms.

The Investigative Committee on Wednesday announced his arrest in absentia and called for an international manhunt.

Vladimir Markin, spokesman for the committee, said in a statement that Russia will take ``all the legal means'' at its disposal to hunt down Khodorkovsky ``no matter where the person accused of grave crimes is hiding: in Russia, abroad, or even in the Antarctic.''

A spokeswoman for Khodorkovsky, Maria Logan, said he now is based in London and was unlikely to turn himself in.

President Putin's decision to pardon Khodorkovsky just a few months before he was due for release was seen as a goodwill gesture on the eve of Russia's Winter Games in Sochi in 2014.

Putin's spokesman Dmitry Peskov has insisted that the president did not have the information about Khodorkovsky's alleged involvement in the 1998 when he pardoned him in December 2013.

Peskov also said that the decision to re-launch the probe and put Khodorkovsky on the wanted list was made by the investigators and that Putin was not involved in it. (AP)