MOSCOW — President Vladimir V. Putin said on Thursday that Russia could soon free its most famous prisoner, Mikhail B. Khodorkovsky, the former chief executive of Yukos Oil, whose arrest and jailing 10 years ago signaled an authoritarian turn in the nation’s modern history.

The release of Mr. Khodorkovsky, once Russia’s richest man and an aspiring political rival, would be an unexpected and striking reversal for Mr. Putin. For a decade, he has shown no signs of sympathy, let alone mercy, as the authorities dismantled Mr. Khodorkovsky’s company and pursued criminal charges — even as recently as this month — that seemed intended to keep him in prison for life.

Mr. Putin, who commands singular political authority here, now appears to have the confidence to risk freeing a man who even in prison has persisted as one of his harshest political critics and who still has the will and financial resources to challenge not only the seizure of his company’s assets but Mr. Putin’s power. Mr. Putin may also have an eye to presenting a positive image to the outside world ahead of the Winter Olympics, which start in the Russian city of Sochi on Feb. 7.

Freedom would represent a new, if uncertain, chapter for Mr. Khodorkovsky, who plunged from almost unimaginable wealth to a jail cell in the Karelia region near Finland, but still managed to maintain some visibility, including writing opinion articles for various newspapers and keeping a website, mostly detailing his case. With a fortune abroad that he managed to maintain after his arrest, Mr. Khodorkovsky could also have an opportunity to once again become an outspoken public figure, presumably with more caution than in the past.