"He has since been actively avoiding police," said Mr Shields. "Marsters is considered armed and dangerous and should not be approached by any members of the public."
Marsters is an associate of the Killer Beez gang and a member of the Otara-based UMF gang.
Police said they were investigating an allegation that Marsters was involved in "another serious violence offence involving firearms", understood to be a shooting.
Marsters is described as a solidly built, muscular Maori, about 180cm tall, with a close-shaven haircut.
He has a tattoo on his upper left arm that says "Unknown Crims Up" with a picture of playing cards.
Can you help?
If you see this man do not approach him. Dial 111 or call Crimestoppers on 0800-555-111.