Police in New Zealand say they have found a shovel they had previously said was related to the Grace Millane murder investigation.

The item was recovered by detectives on Thursday, Detective Inspector Scott Beard said.

Grace Millane was last seen on December 1. Her body was found in bushland outside Auckland a week later. Credit:Stuff/Supplied

"It was located and seized in the central west Auckland area," he said.

On Tuesday police asking the public to contact them if they had come across the Atlas Trade shovel.