MOSCOW (Reuters) - Supporters of jailed ex-oil tycoon Mikhail Khodorkovsky gathered in Moscow on Wednesday to mark his fiftieth birthday and one news website reported that 46 people were arrested.
Chanting: "Freedom for political prisoners!," some 200 protesters rallied amid speculation that the fierce Putin critic could face a fresh criminal case that would prevent his scheduled release in October 2014.
There was no immediate confirmation from the police of the arrest of 46 people, reported by the popular Lenta.ru news site.
Khodorkovsky, once Russia's richest man, has been behind bars since his arrest in 2003. He is serving time for tax evasion and money laundering, a punishment seen by critics of President Vladimir Putin as a political vendetta.
"As long as Putin is in power, they won't free him. This is Putin's personal enemy," said Robert, a 76-year-old scientist at the protest.
Speculation of a possible third case against Khodorkovsky increased when a respected economist, Sergei Guriev, fled Russia last month after being questioned by state investigators in a case involving Yukos, the now-defunct oil company that used to be headed by Khodorkovsky.
Russian channel NTV, known for mudslinging documentaries about Kremlin foes, showed a program this week on the murder in 1998 of the mayor of the city where Yukos was once based.
A former senior Yukos security officer was convicted of involvement in the murder. In 2010, Putin publicly hinted he believed Khodorkovsky was behind the killing.
(Reporting by Lyudmila Danilova and Gabriela Baczynska; Editing by Robin Pomeroy)