Police said it was necessary for interviewers to leave the room from time to time to consult colleagues or view files. However, it was standard practice to ensure the person detained is "observed by a colleague".
The details around where the police officers were and what security there was at the time Makiri escaped are being investigated.
"The fact he was able to abscond the station and remain at large for some days is regrettable and well below the standard required by the Auckland City District Commander," a police spokeswoman said.
Superintendent Mike Clement, Auckland City District Commander, requested the locks be removed from interview room doors last year because they were "inappropriately fitted out".
An internal investigation will determine whether the detective who had Makiri in custody will undergo disciplinary action.
Makiri now faces charges of escaping, kidnapping, injuring with intent to injure and dishonestly taking a motor vehicle. He will appear in court this month.