"Our heartfelt condolences go to Wayne's family. Out of respect for Wayne's family, we will not be making any further comment at this stage."
It's understood he died at the Queenstown SBS branch.
Evans leaves behind four sons, aged 14 to 24, and a wife, Nicola.
In a profile interview with the Business Herald just before Christmas, he said he was an avid long-distance swimmer, having become the seventh person to swim Foveaux Strait in 2013.
He was preparing to swim Cook Strait next month and was in the middle of a training regime that involved notching up 30km to 50km a week in the pool
Evans said that pushing himself physically helped relieve stress.
"The job I've got is quite a cerebral one and it's great to be able to relieve some stress through a physical outlet," he said.
He said of his family: "If you think about life's achievements, something I'm immensely proud of is my boys - they're resilient, self-reliant, intelligent and articulate people who engage with people quite readily. I think I've done my job."
Invercargill-born Evans became SBS' chief executive in 2014.
Bankers Association chief executive Kirk Hope said Evans was greatly admired for his leadership and longstanding contribution to the banking and finance sectors.
"He led with integrity, vitality and a passion for people," Hope said. "On a personal level, I have always appreciated his collegiality, and hold a deep respect for his personal achievements and professional experience."
He said Evans' "positive energy and tenacity" would be greatly missed.
Evans first joined SBS as an insurance clerk in 1984 after leaving high school.
He moved through a range of roles in his first, nine-year stint with SBS, ending up as assistant accountant, where he designed the banking system the lender still uses today.
He then took up a business analyst role with the local health board, before going back into finance as ANZ's Southland district manager.
Evans ended up as head of marketing, a role he left in 1998 to become chief executive of GE Money.
His path back to SBS was provided by Finance Now, a joint venture with the bank he co-founded in 2000.
He was Finance Now's chief executive before being appointed to the helm of SBS in 2014, where he replaced long-serving former CEO Ross Smith.