Jose Abudo said the places he visited between April 2015 and March 2016 had serious problems, including leaking roofs, a lack of ventilation and toilets with flushes that did not work.
He said that tn the prison in the northern city of Lichinga, for example, the prisoners were kept indoors 24 hours a day, because the prison wall was so low guards feared the inmates would escape.
With no exposure to sunlight, the prisoners there were in danger of vitamin D deficiency, which could weaken their bones and prevent their blood from clotting, Mr Abudo added.
In several police cells he visited in Niassa, Cabo Delgado, Nampula and Tete provinces, the floors on which the prisoners were obliged to sleep became soaked on rainy days.
While prisoners held in jails run by the prison services received meals regularly, he found that those held in police cells were less fortunate as food was not covered by the police budget.
In some cases, individual policemen bought food from their own wages to prevent prisoners from starving to death, he said.