Polygraph tests are often used by Employers when contemplating disciplinary action. However, the age-old questions must be asked, “Can an Employer dismiss an Employee solely for failing a polygraph test? Under what circumstances can it be used? And when can an Employer rely on the results of a polygraph test?”

In answering these questions, it is essential to note that an Employee cannot be coerced or bullied into taking a polygraph test. The Employee must give written consent.

The following is also essential:

  1. The Employee must be informed that the test is entirely voluntary.
  2. Only questions that have been discussed prior to the test will be asked during it. The polygrapher is the only person who is permitted to ask the questions.
  3. If necessary, the Employee has the right to have an interpreter in the room.
  4. The Employee may not be abused or threatened during the test.

Employees who fail a polygraph test cannot be dismissed solely on that basis, as results aren’t always one hundred percent (100%) accurate. The results of a polygraph test can only be used in conjunction with other corroborative evidence to justify a dismissal.

The Labour Appeal Court dealt with this issue in DHL Supply Chain (Pty) Ltd v De Beer No and Others (2014) (LAC), where it held that the mere fact that an Employee has failed a polygraph test is not in itself sufficient to find an Employee guilty of dishonesty. The onus further rests on the Employer to lead expert evidence to prove the polygraph test’s cogency and accuracy.

In Goldplat Recovery (Pty) Ltd v Commission for Conciliation, Mediation, and Arbitration & Others (26 January 2021), the Labour Court also addressed this issue. A gold concentrate worth approximately eight-hundred and fifty thousand Rand (R850 000) was stolen by a syndicate. Each Employee who worked in a restricted area was subjected to a polygraph test. Only one Employee failed the test, was charged with misconduct, and was eventually dismissed. This Employee filed an unfair dismissal complaint with the Commission for Conciliation, Mediation and Arbitration (CCMA). The Commissioner ruled that the dismissal was unjust and awarded the Employee the maximum compensation. The Commissioner found no direct evidence that implicated the Employee, and the Employer’s assumption that they were guilty because they failed a polygraph test amounted to speculation.

The Employer took the finding on review to the Labour Court.  The Court had to decide if a reasonable decision-maker on the same material facts would have made the same finding as the Commissioner.

The Labour Court referred to the DHL Supply Chain case when discussing the reliability of polygraph tests. It determined that because the Employer failed to call an expert witness and relied solely on the polygraph results to establish the Employee’s guilt. The Commissioner’s findings were upheld, and the review application was dismissed with costs.

Employers should thus exercise caution when using polygraph tests to discipline and ultimately dismiss an Employee who fails the test. The use of failed polygraph tests alone will not suffice to prove that an Employee is guilty of misconduct or has lied. A polygraph test is only relevant if it corroborates other evidence that an Employee is guilty of misconduct.

Article by Sharé Hassan

Dispute Resolution Official – Gqeberha