If you’re an employer or HR professional considering a polygraph test in South Africa, one of your first questions might be:
“Is this legal?”
The short answer: Yes—but there are strict rules.
While polygraph results are not accepted as sole evidence in criminal courts, they are widely used in the private sector to support investigations, manage disputes, and even influence disciplinary outcomes.
Here’s what South African law says about lie detection in the workplace:
✅ What’s Allowed – and What’s Not:
- Voluntary Participation Only
A polygraph test can never be forced. The subject must give written consent and fully understand the process beforehand. - Legitimate Business Use
Employers use polygraphs to investigate theft, fraud, dishonesty, or as part of pre-employment screening, especially in security-sensitive industries. - CCMA and Disciplinary Hearings
While a failed polygraph result alone will not always prove guilt, it can be considered alongside other evidence in CCMA or internal hearings. - Confidentiality Matters
Results must only be shared with authorised parties. Confidentiality is not just ethical, it’s a legal requirement.
⚠️ What It Doesn’t Mean:
Polygraph tests don’t replace law enforcement. They’re tools for internal clarity—used by companies, law firms, and investigators to assess risk, guide decisions, or support HR action.
When done ethically and professionally, polygraph testing becomes a powerful—and fully lawful—way to protect your business and staff.
Need to investigate an issue, but unsure what’s legally allowed? We’ll guide you through the process.
📝 Contact us to learn how polygraph testing fits within South African labour law.
👉 Start here