Smuggler pigeon locked up
The bird is a pet of one of the inmates and it's thought tiny bags containing heroin had been tied to its legs.
The bird's owner and three other inmates later tested positive for the drug.
"We suspect that the pigeon carried the drugs from Tuzla," said Deputy Warden Josip Pojavnik - referring to a town more than 40 miles away.
"We do not know what to do with the pigeon," Pojavnik added. "But for the time being it will remain behind bars."