This was said by Arkady Gostjev, head of the Russian prison service, to the state-run Russian news agency Tass.
Since the start of Russia's full-scale war of aggression against Ukraine, many prisoners have been recruited into the Russian army, with the promise of harsher punishment if they survived.
According to Gostjev, the downward trend is also due to more Russians receiving other types of punishment, such as suspended sentences and penal servitude.
Prisoners returning from the front have led to an increase in various forms of violent crime and social unrest in Russia.
A total of 282,000 people are currently in Russian prisons, a decrease of nearly 40 percent compared to 2021.
