Duffie, a former standout First XV rugby player with St Kentigern’s College, has inked a two-year deal with North Harbour and the Blues and has spurned the interest shown in him by the Warriors.
Duffie has suffered a number of serious injuries after making his first grade debut in 2010. He made a remarkable return to the Storm late in the regular season and has produced a string of impressive displays.
Duffie will link up with the Blues once his season with the Storm finishes.
Meanwhile another potential candidate to bolster the Warriors back-line stocks has re-signed with his current club. Panthers utility back Will Smith has agreed to a new deal that will keep him at the foot of the Blue Mountains.
Warriors managing director Jim Doyle is chasing another three players to round out his 2016 roster, with outside backs high on the agenda.