It is understood that the Crusaders were also chasing Hurricanes wing Alapati Leiua but were turned down.
While no one from the franchise would confirm Savea's signing, it is understood that they are close to confirming it. The impending announcement will be a huge blow to the Hurricanes, who have supported Savea since an alleged domestic violence incident in April.
Savea burst on to the test scene last year, scoring three tries on debut against Ireland at Eden Park. He has carried on his incredible rate since, with 13 tries in 13 tests.
The Crusaders this season got by without making any big signings - the addition of the 1.9m, 104kg Savea suggesting they have realised they need some heavy artillery in order to go all the way following their exit to the Chiefs in Hamilton.
Colin Slade will rejoin them from the Highlanders as a replacement for Carter, with Tom Taylor having put in an assured performance on debut for the All Blacks last weekend.
In what is yet another blow for the Hurricanes, Taranaki will place their allegiance with the Chiefs from next season.