The police in Fiji say they are confident they will uncover how five inmates escaped from the Medium Corrections Facility in Naboro, near Suva.
The five men escaped on Monday last week, and four of the group were caught on an island near Suva on Friday night.
Local media reports five men have appeared in the Suva Magistrates Court charged with aggravated robbery and harbouring the prison escapees.
One of the inmates, Isoa Waqa, is still on the run.
The Acting Assistant Police Commissioner and the Police Chief of Operations, Rusiate Tudravu, says officers are looking into whether someone inside the prison helped the inmates.
"That is part of the investigation. We are trying to get to the bottom of all this. Our intention through the investigation is to find out who is the mastermind of all this. That is where the line of investigation is going into. I will get to the bottom of it."
The Assistant Police Commissioner says the Police and the Corrections Service are both investigating.