The Russian Prosecutor General's office said Wednesday that it was investigating the possible role of a former top owner in the Yukos oil company in the poisoning death of ex-Russian spy Alexander Litvinenko.

The prosecutor's office said in a statement that Leonid Nevzlin, who is living in exile in Israel, and other Yukos figures wanted by Russia, could have ordered Litvinenko's murder in London last month.

For more news on this case, as well as news from Europe, click here.

It did not give any details of the allegations against Nevzlin. Russia has unsuccessfully pressed for the extradition of a number of Kremlin critics in recent years, including tycoon Boris Berezovsky, who lives in Britain.

The statement added prosecutors had formed a special investigative unit and were preparing to file international requests for assistance in the case and possible extradition demands.

Litvinenko died in London on Nov. 23 after he was exposed to a rare radioactive element, polonium-210. In a deathbed statement, he accused President Vladimir Putin of ordering his murder, allegations which the Kremlin has dismissed as absurd.

Nevzlin, a Russian exile living in Israel, told the AP last month that Litvinenko had given him a document related to Yukos and said he believed the agent's killing was tied to his investigations into the company.

His lawyer, Dmitry Kharitonov, dismissed the allegations of Nevzlin's involvement in the death of Litvinenko as a provocation.

"It's the easiest thing for the prosecutor general's office to pin all crimes on people living outside Russia," he said according to RIA-Novosti. "This is just another provocation."

Nevzlin fled Russia after authorities launched a campaign against Yukos, once Russia's top oil producer, in 2003. The company's founder, Mikhail Khodorkovsky, is serving an eight-year sentence for fraud and tax evasion and Yukos' main assets now belong to the state oil group Rosneft.