It’s an erroneous claim made so often that you may well have come to believe it.

And that would be a great pity, if you have an interest in any of these business objectives:

  • Distinguishing false claims and allegations from facts
  • Ensuring that those involved in wrongdoing are identified in a way that appropriate action can be taken
  • Reducing the likelihood that the people you employ will engage in unethical activity.

What we advise our clients, with confidence, is this:

  1. Polygraph testing is not illegal in South Africa.
  2. It continues to play a pivotal, legitimate role in investigations.
  3. It’s playing an increasing and valuable role in prevention.

We agree wholeheartedly that the courts will not, and should not, conclude that a person is guilty of a crime solely on the basis of a polygraph report. At the same time, this technology plays a number of other legitimate roles as part of an integrated approach to prevention and investigations.

Let’s start with distinguishing false claims from facts.

Simply put, it may be unlawful and undesirable to conclude beyond reasonable doubt that a person is guilty of an offence based solely on a polygraph, but it is not unlawful to attach weight to polygraph evidence as one component of a comprehensive, compelling case when using the employment law test of the balance of probabilities.

As an employer you are likely to be involved, regularly, in decision-making based on the balance of probabilities. Given this, you should welcome the valuable role a polygraph can play in identifying a person as innocent of the allegations against them.

One of our clients, a human resources director, put it like this:

“Voluntary polygraphs made available to those who have been falsely implicated, or to those who wish to disassociate themselves from suspicious activities, play an invaluable role. At worst, a falsely accused person can be the subject of unwarranted disciplinary action. At best, without the polygraph, a cloud of suspicion can linger around the innocent person, impairing the level of trust and respect they previously enjoyed. Having full confidence in the expertise of Justicia Investigation’s specialist polygraphers, our position is that we accept the favourable outcome of a polygraph, unless there is other compelling evidence to the contrary, in which case we probably wouldn’t need a polygraph anyway”.

While fictitious whistleblowing reports remain rare events, the potential for them to be made tends to make line managers and supervisors fearful that company whistleblowing systems will be abused by employees seeking revenge for unpopular decisions. As the HR director explained it to us:

“When we undertake whistleblowing awareness initiatives, it gives managers and supervisors, amongst others in the business, great confidence to know that in the event allegations are made against them, that we will give them the opportunity of undertaking a polygraph if they so wish”.

At Justicia, little gives us more satisfaction than providing an innocent person with the opportunity of clearing their name. In a recent case, a falsely implicated manager put it like this, “It was not something I would want to do again in a hurry (referring to the polygraph), but if I hadn’t been able to clear my name I would have had to resign from a job I love because I wouldn’t be able to bear the thought that suspicion would swirl around me forever”.

As we mentioned at the outset, polygraphs continue to play an important role in successful workplace investigations. This is because the use of the polygraph can help to:

  • Polygraphs narrow the search for the wrongdoers as the pool of those potentially involved is reduced (in the process shortening investigation duration and costs)
  • Refine our hypotheses as to who did what and how (enabling more targeted forensic work, often leading to the uncovering of hard evidence without needing to polygraph the reluctant wrongdoer/s)
  • Prompt guilty parties to make confession statements during pre-polygraph interviews
  • Prompt guilty parties to make confession statements when they discover that they have not passed a polygraph (a surprising number of people believe they can bluff the polygraph, and fail).

Finally, polygraphs are helping us to prevent and deter unethical activity in the workplace.

This is happening in at least two ways:

  • Increasingly employers are requesting that candidates undertake pre-employment polygraphs to limit the likelihood that they employ people with a track record of unethical behaviour. These are employers who understand that the time it takes for a conviction to be secured and recorded means that a traditional criminal check can be providing a false sense of confidence. They are also employers who understand that a significant pattern of unethical activity can go undetected by the justice system. Employing people without a history of wrongdoing ensures that at least half the workplace ethics battle is won.
  • Random polygraphing of employees in high-risk roles has a deterring effect on those who may otherwise become tempted to abuse their positions. As one security guard explained to us, “Because we have random polygraphs, I had no choice but to blow the whistle when a syndicate member started pressurising me for information about the timing of my perimeter patrols.”

At Justicia Investigations our polygraphers are highly skilled and experienced, having received advanced training in the technology. Their service is in high demand by a diverse range of clients who regularly make use of our polygraph service as part of their workplace investigations.

And it is not only the employers who have faith in our service.  One of our favourite moments was when a power tool went missing on a remote site of a large organisation. As the manager started to ask employees if they knew what had happened to the power tool, the shop steward said this: “Call those people (referring to Justicia who had conducted investigations at the site previously) to come here with their polygraph machine, we don’t want to be doubting each other, we must get to the bottom of this as fast as possible”.


If you have been of the impression that the polygraph has no role to play in your workplace wrongdoing prevention strategy or workplace investigations, we hope our insights have given you new interest in the legitimate use of the technology.

Contact us for a discussion: email us at or call +27 (086) 000 5 111.

Learn more about our integrated corporate crime prevention and investigations service at