The Federal Prison Service's chief has been fired after less than three years at the helm, the Kremlin said late Tuesday.
Alexander Reimer, 54, formerly police chief of the Samara region, had been appointed to improve the nation's notorious prison system in August 2009, after guards were linked to the violent deaths of several inmates.
But shortly after Reimer was appointed, lawyer Sergei Magnitsky's death in pretrial detention brought criticism of the system to a boiling point.
Magnitsky was jailed on tax evasion charges soon after accusing tax and police officials of embezzling $230 million. He died of heart failure after about a year in custody.
An independent inquiry ordered by the Kremlin revealed that Magnitsky died after being severely beaten by guards.
In March, convicted murderer Alexei Shestakov escaped from a Vologda region prison by climbing onto a rope that had been dropped by a hovering helicopter commandeered by accomplices.
An investigation found that the escape could not have taken place without the collaboration of prison officials.
"Reimer had a good start. He wanted to improve the living conditions in prisons, but then he got caught up in the system. He became a part of it," Lyudmila Alexeyeva, head of the Moscow Helsinki Group, said in comments carried by Interfax.
Gennady Korniyenko, 57, who headed the State Courier Service since 2002, will now become the top prison official. Like his predecessor, Korniyenko has never worked in the prison system.
