Freed Russian former oil tycoon Mikhail Khodorkovsky, right, poses with father, Boris, and son Pavel, before speaking at a news conference in Berlin. (Michael Kappeler/Pool via Reuters)

Mikhail Khodor­kov­sky has yet to decide how he will spend the rest of his life, but one thing is clear: The former Russian oil tycoon, who castigated the Kremlin throughout the decade he spent in prison, is not going into politics. Instead, he says, he will devote his time to social causes and helping secure the release of other political prisoners.

Thirty-six hours after his dramatic release from prison, Kho­dorkovsky told reporters at a packed news conference in Berlin that he was grateful for the support he received during his long incarceration.

Once Russia’s richest man, Kho­dorkovsky was arrested at gunpoint at a Siberian airport in 2003 and charged with massive fraud and tax evasion. His supporters say the case, which bankrupted Yukos, the oil company he founded, was orchestrated by the Kremlin to punish him for his political activities.

Russian President Vladi­mir Putin granted his foe a surprise pardon Friday. He was released and flown to Germany on a private jet.

Khodorkovsky, who once said the worst thing about prison was being deprived of sunshine, looked pale Sunday but wore the beguiling smile famous from his days as Russia’s most successful oilman. Speaking in Russian, he stressed that he has no intention of challenging Putin for the Russian presidency. “I am not going to get involved in a struggle for power. That’s not for me,” he said.

The news conference was held at Berlin’s Checkpoint Charlie Museum, which documents successful escapes from Soviet-dominated East Germany to the West during the Cold War.

Khodorkovsky said his release should not deflect attention from other political prisoners in Russia. He said he would do “everything possible” to help secure their freedom.

With his sentence due to expire in August 2014, Khodorkovsky knew that German diplomats were trying to negotiate his early release. Simultaneously, however, Russian prosecutors were preparing fresh charges that could have kept him in jail for much longer.

He said it was a total surprise when the prison commandant woke him in his cell at 2 a.m. Friday and said, “You’re going home.” Only when he was aboard a helicopter bound for St. Petersburg, he said, did he learn that his final destination would be in Germany.

Hans-Dietrich Genscher, a former German foreign minister, acted as a mediator and played a critical role in getting Putin to agree that an appeal for pardon by Khodorkovsky would not be construed as an admission of guilt.

Khodorkovsky explained that he had always held out against appealing for clemency because, if seen as an admission of guilt, the plea could be used by Russian prosecutors as a pretext to charge his former colleagues at Yukos.

A Russian state television broadcast Sunday evening vilified Khodorkovsky, recounting how the ex-tycoon had grown rich in the 1990s — the wild early years of Russian capitalism — by dishonestly “milking the system.”

The “delight that met Khodor­kovsky in Germany was unlikely to be shared in Yugansk,” the Siberian oil town where Yukos was formerly based, said Dmitry Kiselyov, a prominent television journalist recently appointed to head Russia’s new state media conglomerate.

Khodorkovsky said he had no plans to relaunch his business career. He said he would devote his time to helping people held in Russian prisons and hinted that he might seek a role in civil society.

“My financial situation doesn’t require me to work just to earn some more money,” he said. “It’s so important that Russian society changes a little, so that we all fare better.”

Despite being one of the Kremlin’s fiercest critics, Khodorkovsky avoided castigating Putin. He allowed himself to laugh when the news conference anchor said Russia’s president deserved thanks for allowing his early release.

Khodorkovsky said experience had taught him that the “games people play are really tough” in Russia. He said he was grateful that the judicial system, while dealing exceptionally harshly with his case, had stopped short of punishing his family.

Putin’s press secretary, Dmitry Peskov, has said that Khodorkovsky is welcome to return to Russia any time. But the ex-tycoon ruled out a return home until he had obtained legal guarantees that he also would be free to leave at will. An outstanding $550 million lawsuit against him could provide Russian prosecutors with a pretext for banning him from foreign travel, he said.

Asked whether Western leaders should boycott the 2014 Winter Olympics, which Russia will host in February in Sochi, Khodorkovsky said it would be a pity to spoil an event that is followed by millions and is a “celebration of sport.”

At the same time, he added, the Sochi Games should not “be a great party for Putin.”