No idea: not enough words to pin it down, tho' I could understand your suggestion of S African accent.
There was a lot of discussion about Scottish actor, David Tennant's accent in a recent UK TV series about Donald Nielsen (serial killer) with some people thinking it was strange, but others saying he was spot on for someone who had originally come from Fraserburgh in NE Scotland, but then spent a good few years in London, which had sort of "diluted" his accent.
Then I got puzzled by the accent of one of our health advisers who is frequently seen on TV in Scotland, Linda Bauld: it turns out she has spent most of her life in Canada and Scotland, so her accent is a delightful mix of both.