Riihimäki District Court found on Friday that requiring inmates returning from furlough to wear special overalls that keep bodily excretions inside are not a violation of their human dignity.
The former warden of Riihimäki Prison and two prison officers were acquitted of charges brought against them by a group of inmates. The court also rejected their demands for damages.
The use of the overalls had been suspended pending the court's decision. The Criminal Sanctions Agency says that the resumption of the use of the garment will be considered.
The court found that the overalls were used properly at the time for the proper purpose - that of preventing a prisoner returning from a furlough from bringing drugs into the prison internally.
Suspicion of drug smuggling in each of the cases was based on a number of factors, such as tipoffs from the police, and the prison's own intelligence-gathering.
At times the prisoners had to defecate inside the overalls, but the court did not find evidence that the guards had deliberately delayed going to the assistance of a prisoner in solitary confinement wearing the overall.
"Using the overall was not intended to humiliate the prisoners, or to treat them in an otherwise improper manner during isolation, even though monitoring the prisoner during isolation was not always implemented with sufficient caution", the court notes.
Jaakko Kopra, the warden of Riihimäki Prison at the time, and two top officials were charged with neglecting their official duties and violating the prisoners' dignity in the matter.
None of the prisoners seeking damages were found to be carrying drugs.