At a ceremony at the Pike River mine on the West Coast on Friday,what appeared to be diamond ring was spotted on Ardern's left hand - but on her middle finger. It is understood she has been wearing the ring since the engagement.
Ardern,38,and Gayford,41,met at an awards event in 2012,and last year she gave birth to their first child together,daughter Neve Te Aroha Ardern Gayford,who turns one next month.