The majority of employers are under the impression that the results of a polygraph test alone are sufficient to prove their case against the employee during a disciplinary hearing. This is unfortunately not the case.
When it comes to polygraph tests, there is no legislation guiding us in that regard, and therefore we have to rely solely on case law. When the employer intends to use a Polygraph test, he/she needs to consider some important factors. Below is an elaboration on the two relevant factors:
- A polygraph test cannot prove that the employee is telling a lie.
The test only indicates deception in the employee’s answers during the questions that the examiner asks. When telling a lie, the employee will feel nervous which will result in the rise of the heartbeat, increase in blood pressure etc. In Amalgamated Pharmaceuticals Ltd v Grobler NO and Others, it was decided that the polygraph test is only an indication of deception and could not prove the employee’s guilt.
- The employee needs to consent to the test in writing.
- The test results alone are insufficient to prove the misconduct.
The polygraph test results are regarded as circumstantial evidence, and as such, the employer cannot solely rely on the test results themselves. The employer will have to submit supporting evidence as well to prove the misconduct. In the case of Sosibo & Others v Ceramic Tile Market the commissioner stated that the sole reliance on the test results is insufficient to discharge the onus of proof on the employer.
- The examiner should be informed by the employer what type of questions he/she should ask.
- The employee’s rights should be explained to him/her before the test.
- The examiner should testify at the disciplinary hearing and arbitration.
Therefore, the employer cannot solely rely on the polygraph test results during a disciplinary hearing to prove his case against the employee, and as such, he will also need to submit supporting evidence to prove the employee’s guilt.
Recognition for this article is given to the original author Johanette Rheeder at Johanette Rheeder Attorneys (Published on the SA Labour Guide website.)
About the Author:
Frikkie van Tonder obtained a B.Comm Law and LLB degree from the University of the Free State. In April 2012, the author was admitted as an Attorney in die Free State High Court Bloemfontein where he then joined SEESA Bloemfontein in 2015 in the labour department where he specializes in labour law.