Europe's leading human rights body has issued a report slamming conditions in Greek prisons and migrant detention centers, saying no improvements have been made despite recommendations made two years ago.

The Council of Europe's Committee for the Prevention of Torture, or CPT, published the report Thursday based on visits to Greek detention centers in April 2013.

In its report, the CPT also noted increasing mistreatment of suspects by police during the arrest procedure, chronic overcrowding in prisons and migrant detention centers and a severe staffing shortage of prison guards.

The CPT also released the Greek government's response, in which authorities detail measures being taken to tackle the problems and reject criticism about understaffing in penitentiaries.