Russia says the recent rise in pretrial detentions is due to the increasing severity of judges toward people accused of minor offenses.
Anatoly Rudy, the deputy head of Russia's prison service, said on January 2 that the country has seen a "steady growth" in the number of people remanded in custody for minor crimes over the past two years.
According to official figures, the number of detained or convicted people grew by 4,800 in 2014.
About 20 percent of those arrested are released from pretrial detention centers.
Russia's prison population currently stands at more than 670,000 people.