The book "Bloodstone" by Irna van Zyl.

In Irna van Zyl's detective novel "Bloodstone" the action develops at an unprecedented speed and unfolds first in London, then in Hermanus, then moves to Cape Town, then to Antwerp and so on. It is no accident that the mother of Detective Sergeant Storm van Merwe was hit by a train... The reason and purpose of all the assassinations preceding and following this incident is the search for the red diamond, the smuggling of diamonds, and behind them are a businessman mired in corruption and a false prophet trying to "transform" the world.