It takes hours of investigative work to take down a pigeon operation.
The pigeon was a pet of one of the inmates. When he and three other prisoners in jail tested positive for heroin, disciplinary proceedings were launched.
It is thought that the drugs were stuffed into tiny bags and attached to the pigeon's legs.
"We suspect that the pigeon carried the drugs from Tuzla", a town around 70 kilometres more than 40 miles northeast of Zenica in central Bosnia, added Pojavnik.
Fine, the prisoners have been punished. But what about the brains of the operation?
The pigeon is now in custody while police investigate who might have loaded it with drugs.
"We do not know what to do with the pigeon, but for the time being it will remain behind bars," Pojavnik said.
Throw away the key! Pigeons who break the law shouldn't be treated any differently than a man, pig or donkey that breaks the law.