Mikhail Khodorkovsky, who backed an opposition party, has been in jail since 2003 and was convicted in 2005 on charges of tax evasion and fraud. Russia has faced wide criticism over his treatment, with the United States and others accusing it of "selective prosecution" and abuse of the legal system.
His son, in his letter to policymakers at Davos, called on them to raise the issue of the former Yukos chief executive's continued imprisonment and urge support for the rule of law in Russia.
"Ending corruption is not just a human rights issue," Pavel Khodorkovsky said. "The proliferation of corruption remains a huge impediment to direct foreign investment.
"Both U.S. and Russian officials have publicly acknowledged Russia's weak property rights and rampant corruption are reasons to avoid doing business in Russia. This is thwarting job creation and starving Russian businesses of the capital they need to grow."
Medvedev's comments come amid frosty relations with the United States after Putin signed a law in December prohibiting Americans from adopting Russian children.
The move by Russian politicians was widely seen as retaliation for a law that U.S. President Barack Obama signed December 14. That bill, called the Magnitsky Act, imposes U.S. travel and financial restrictions on those it considers human rights abusers in Russia.