MOSCOW, April 5 (RIA Novosti) - Over 4,000 people died in Russian correctional facilities in 2009, a senior prosecutor has said.

"Last year alone, 4,150 people died in correctional facilities. In the same period, 521 people died in pre-trial detention centres," Deputy Prosecutor General Yevgeny Zabarchuk said in an interview in the Rossiiskaya Gazeta newspaper to be published on Tuesday.

There are currently 861,867 people imprisoned across Russia. The country's prisons are notorious for their overcrowding and the high incidence of infectious diseases.

"This problem is deserving of particular attention," he said.

"After all, the large majority of the inmates are not elderly people...but those at an age that should see them at the peak of their strength. Nevertheless, many of them do not live until their release date or come out disabled."

"There is no modern medical equipment in many pre-trial detention centers," he went on, adding that in some facilities medical staff were entirely unqualified.

"Inmates, even incorrigible criminals, remain citizens of our country and have not been deprived of the right to medical aid," he noted.