His death this morning has been confirmed by production company South Pacific Pictures.
Samoan-born Mr Magasiva played the part of nurse Vinnie Kruse in Shortland Street.
He also played the lead role in the 2006 film, Sione's Wedding and was in Power Rangers.
In the early hours of this morning, police were called to the sudden death in central Wellington.
Police said there are no suspicious circumstances and the death would be referred to the coroner.