Inspectors from the Council of Europe who visited over a dozen police stations, prisons, and psychiatric hospitals described conditions in several as "inhuman or degrading."
The Council of Europe, which undertook its inspection in 2006, released its report today in line with its policy of allowing the country in question to respond and decide whether to make the findings public.
The human rights watchdog said it found overcrowding in one prison in the city of Bacau meant inmates had on average around 1 meter of cell space, compared to the minimum 4.2 meters recommended by the group.
Cells for minors in the same prison were "an affront to human dignity," the report said, highlighting one where 26 boys had to share 12 "threadbare beds infested with lice."
Investigators also said electroshock and strait jackets were used in psychiatric hospitals where some patients suffered from malnutrition. They said they worried some were being used as guinea pigs in clinical medical trials.
Romanian government officials were not available to comment on the findings into the country's prisons.
However, they said conditions at psychiatric hospitals and other special treatment units had improved significantly following the country's EU entry in 2007, helped by a hefty investment of around 100 million euros.
"It is weird to come up with three-year-old findings and present them as the country's current shortcomings," outgoing Health Minister Eugen Nicolaescu told Reuters. "The treatment facilities have been modernized, practices used are only modern practices."
Along with the report, the human rights watchdog released a response made by Romania in 2007 after the report was finalized, which said it was addressing the problems, and that the accusations of medical testing were "lacking proof."
The EU says Romania has made progress in improving its correctional institutions, which were a major concern during the country's bid to join the 27-member bloc.