C&A Friedlander Attorneys

Written by:  Cornel van der Westhuizen

Employers seeking clues as to the possible misconduct of their employees have often resorted to polygraph testing. These tests may provide some insight into an employee’s guilt or suspected unlawful actions, although the answers they receive may not be as reliable as the average person might think.

Movies and television shows often depict the shady criminal buckling under the pressure of a screeching polygraph machine, but in reality these tests are far from the smoking gun they purport to be. In fact, the American Psychological Association has formally stated that the majority of psychologists are in agreement that the alleged accuracy of polygraph tests to detect lies is not backed by sufficient evidence.

The use of polygraph testing in South Africa is a relatively novel concept that has been gaining popularity as South Africa does not regulate the use of polygraph tests in employment matters or protect the employee’s right against the abuse of the testing. Labour legislation has failed to address the subject yet.

However, it remains unconstitutional to compel a person to undergo a polygraph examination, unless they consent to it, in which case consent must be given in writing.

Common practice at the CCMA further dictates that the person should be informed that:

  • the examinations are voluntary;
  • only prior stated questions will be used;
  • they have a right to an interpreter;
  • should they prefer, another person may be present during the examination, provided that they do not interfere with the proceedings;
  • the testing may not be abused;
  • no discrimination will be allowed;
  • and they may not be threatened.

The CCMA has accepted polygraph practitioners as expert witnesses whose evidence needs to be tested for reliability, and polygraph results as evidence to be corroborated by the practitioner. The Commissioner has a duty to ascertain the admissibility and reliability of the polygraph evidence. Common practice has further established that polygraph tests cannot be interpreted as implying guilt, but may be regarded as an aggravating factor if other evidence of misconduct substantiates the test results. Polygraph test results alone are not proof of guilt and can only be used in support of other more reliable evidence.

The Courts have held that polygraph tests are non-conclusive and non-corroborative in establishing guilt in the absence of expert evidence. To establish their reliability, expert evidence is needed to corroborate the polygraph test results.[1] The Courts have further held that the mere fact that an employee fails a polygraph test is not in itself sufficient to find that employee guilty of dishonesty.[2]

Employers should only use this potentially expensive tool when there is a reasonable suspicion that the employee committed an unlawful act and those acts have caused the employer financial or reputational damage. Polygraph testing can be further utilised where there is possible breakdown in trust with an employee, where trust is a vital component to the employer employee relationship, or where the employee is suspected of having committed a serious breach of their contract of employment or gross misconduct.

If employers intend to use polygraph testing, they must ensure that employees have consented to it in writing and have been fully informed of their rights. This consent and all pertinent information regarding polygraph testing can be included in a contract of employment and should be included in official company policy.

  • [1] DHL Supply Chain (Pty) Ltd v De Beer NO and Others (DA4/2013) [2014] ZALAC 15; [2014] 9 BLLR 860 (LAC); (2014) 35 ILJ 2379 (LAC) (13 May 2014)
  • [2] Goldplat Recovery (Pty) Ltd v Commission for Conciliation, Mediation and Arbitration and others [2021] JOL 49890 (LC)

This article is a general information sheet and should not be used or relied on as legal or other professional advice. No liability can be accepted for any errors or omissions nor for any loss or damage arising from reliance upon any information herein. Always contact your legal adviser for specific and detailed advice. Errors and omissions excepted (E&OE).