Police have revealed Mr Yates, known as "Big Boy", was wanted for kidnapping and aggravated robbery. He had access to firearms and should not be approached.
Head of the investigation Detective Inspector Kevin Burke said police were not aware of any issues between the two gang members but if people were aware of something that could help with the investigation they should contact police.
He said the vehicle of interest was being used by Mr Yates and he could have had Mr Moore in the car with him, so sightings were very significant.
"Clearly we believe some significant event has occurred. It's still a missing person enquiry," Mr Burke said.
"Police have been to countless address looking for Mr Moore."
A police team worked through Easter weekend and completed scene examinations at properties in Kaitaia and Peria and had discovered some items of significance. While Mr Burke would not reveal what those items were he said they would help with the investigation.
Mr Moore's family members had not heard from him since March 17 and were becoming increasing concerned for his health as he required medication.
"The longer he is missing the more his family and police become concerned for him," Mr Burke said.
Mr Moore is described as 1.82m tall with dark hair and of solid build. Mr Yates is described as 1.73m tall and of obese build.
Anyone who sees either man is asked to contact police or Crimestoppers on 0800 555 111.
