The Council's Committee for the Prevention of Torture (CPT) said that many of Italy's prisons were "still operating above capacity", and denounced multiple cases of ill treatment.
Prisoners had made allegations of "slaps, punches, kicks and blows with batons", both during arrest and in police custody, according to the CPT, with numerous cases supported by medical reports.
Other inmates reported delays in getting access to a lawyer, informing a third party of their detention, or - in the case of non-Italian speakers - getting information on their rights in their own language.
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The CPT called on Italian authorities to "make formal communication to police officials" to remind them of detainees' rights and inform them that mistreatment would be prosecuted.
Its report also criticized the "excessive" use of solitary confinement, and said this often occurred without guaranteeing adequate monitoring.
Prisoners' rights group Antigone said the CPT report confirmed the issues they had denounced in recent months.
In late July, Antigone reported that 29 Italian inmates had killed themselves since the start of the year, and its president Patrizio Gonnella called for "immediate measures" to be taken, including a review of the use of the isolation system, and increased opportunities for maintaining family relationships.
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A recently-released report by Antigone said the overcrowding rate in Italian prisons was 113 percent (equivalent to 113 detainees per 100 places) and that Italy had one of the lowest ratios of guards to inmates of any European country. In some jails, the overcrowding rate was as high as 185 percent.
At the end of August, riots broke out in a Pisa prison to protest tough living conditions after a 21-year-old hanged himself in his cell.
In 2014, an earlier Council of Europe report revealed that Italy had the second-highest level of prison overcrowding in Europe, with only Serbia performing worse.
It later praised Italy for taking steps to address the problem, noting “an important and continuing drop in the prison population, and an increase in living space” for prisoners.
After a 2013 judgment from the European Court of Human Rights called on Italy to tackle prison overcrowding, the number of inmates was reduced by 11,000 over the following two years, while the number of places available in prisons increased by 2,500.
However, since the start of 2016, the CPT said the population had begun to increase steadily. It said this occurred "largely as a result of increased resort to remand detention, particularly in respect of foreign nationals".