"The nature of the scene and the fact the remains may have been in place for some years make this a challenging investigation."
Members of the public who can help identify the previous owners or occupants of the boarding house are asked to contact police.
"We would like to hear from anyone who previously resided at 3 Marlborough Street, Mt Eden, or anyone who can help us get in touch with those people," Baldwin said.
Scene examinations will continue for the next few days.
Anyone with information is asked to contact Auckland City Police on 105 or contact Crimestoppers anonymously on 0800 555 111.