Watch: NZ police dog finds woman's keys in seconds at Ellerslie Racecourse

A video shows the incredible moment a NZ Police dog finds a missing set of keys in a field within seconds.

Police dog Haven and her handler Grant were out doing article search training at Ellerslie Racecourse when they were approached by a distressed woman who lost her cars keys in the field.

Grant decided to put Haven on the case to sniff out the missing keys and then post a video on the Counties Manukau Police Facebook page.

"It's a good opportunity for Haven to do a little Article Search," Grant says before Haven shoots off to begin her mission.

The video shows Haven scampering around the racecourse trying to sniff out the keys.

Amazingly, within 17 seconds she finds them in the grass.

"Good girl ... yas!" Grant yells in joy.

Haven then runs around in excitement for successfully completing her mission.

The pair then return the keys to the grateful owner.

"Brilliant, good girl," the woman praises the Police dog.

Grant then explains to the woman how Haven is trained to retrieve items as well as humans.