The book was launched at a packed Cornerstone Institute in Salt River on Tuesday, with the families of both September and Lubowski present.
Mary Burton, a tireless fighter for social justice, human rights advocacy group the Black Sash and a commissioner on the Truth and Reconciliation Commission, was also in attendance.
While it is often thought that the three were assassinated by apartheid forces simply because they were freedom fighters, Groenink’s research conducted over 30 years shows that this was not the case.
All three had tried to keep their organisations, the ANC and Swapo, free of wrongdoing. They stood against Mafias that had invaded their movements' inner circles.
They were not only brave anti-apartheid fighters, they were incorruptible, Groenink said.
One of the most explosive revelations in this book concerns the murder of Chris Hani 25 years ago.
Groenink reveals how the police buried evidence from no less than three witnesses who saw another murderer besides Janusz Walus; and how the state's “brave” star witness in all likelihood hadn't even been there when Hani was shot.
Michael Arendse, September’s nephew, thanked Groenink for her efforts to uncover the truth.
“This work is difficult work. It is important work; it is also dangerous work, and she stuck it out for 30 years. Evelyn, on behalf of September’s family, her colleagues and friends, thank you,” he said.
Gabriella Lubowski said over the past 28 years there was not a moment in which she hadn't grappled with this “gross injustice”.
“The first blow was the brutal murder of a man who stood for lifting up the oppressed and poor. The second was that his name was dragged through the mud.
“After the murder, I intuitively knew that something was off.
“Evelyn talks in her book about the silence around Dulcie’s death, and that there was no acknowledgement or appreciation for the hard work and the 100% commitment - what was done for the organisation. With Anton's death, there was that exact same silence,” she said.
Gabriella said she initially thought the silence was because Dulcie was a woman and Anton a white man.
“But now I know it was neither. It is simply the behaviour of humans when they have done something bad or wrong, when they have chosen pure self-interest over the greater good.
“It was indeed a very scary and traumatising time."
Groenink’s book and research were proof that humans have a dark side, she said.
“Evelyn took 30 years to write this book. That’s how long it took to break through all the lies and deceit, and it would have been a woman who would do this kind of work,” she added.
Groenink continued pursuing the truth because of lessons she learnt along the way, she said.
“I learnt very important lessons and it was these lessons that prompted me to go on. You want to know you know they’re lying to you, and you get * ****d because of that - you want the truth and you also get angry.”
As she pursued the cases, Groenink said her initial ideas of what had happened were found to be wrong.
“I jumped to conclusions, like everybody else did - that it was those damn bloodthirsty hit squads sent by the apartheid regime, and they were just doing what they did because they were horrible people and they were killing black people and freedom fighters, all over, and that was all there was to it,” she recalled.
Groenink's book was released in 2001, in Dutch, and a decision was later taken to translate the work and make it available to local audiences.
A planned publication in 2005 could not take place because of legal and physical threats against then intended publisher Jacana that resulted after comments were invited from a number of individuals mentioned in the book.