Shantonette Pillay, ECA(SA) Regional Director, KwaZulu-Natal

By Shantonette Pillay (LLB)(UND), Regional Director, KwaZulu-Natal Region

What are the rights of employers when it comes to polygraph testing; and what rights do employees have when instructed to undergo such a test?

First, we must ask: What is a polygraph? A polygraph is an instrument that measures predictable changes in a person’s body that are associated with stress or deception, such as heart rate, breathing, blood pressure and the electronic conductivity of the skin (emotional sweating). Simply put, it records deception based on the body’s involuntary physical responses to the stress caused by not telling the truth therefore a polygraph test could be used to verify a person’s truthfulness.

Is a polygraph test admissible in legal proceedings? Polygraph tests are inadmissible in criminal cases. Initially, decisions at industrial courts cautioned against relying on polygraph tests as evidence, but this does not mean you are prohibited from using them.

Case 1

In the case of Amalgamated Pharmaceuticals Ltd v Grobler NO and others (2004) 13 LC 1.11.3 the third, fourth and fifth respondents were dismissed for misappropriation of company property. A polygraph test showed that the respondents could be responsible for the serious stock losses suffered by the applicant.

The Labour Court agreed with the reasoning of the Commissioner who found that, in practice, a polygraph does not serve to prove that someone is actually lying, as the questions are often too broad to exclude that which is neither intended nor sought.

And a polygraph test result does not prove that someone is guilty; it is merely an indication of deception.

Case 2

However, the Labour Court and the Commission for Conciliation, Mediation and Arbitration (CCMA) have accepted in cases such as Sosibo and others and CTM (2001) 10 CCMA 2.5.2, that polygraph testing in the workplace is highly contentious and the admissibility of its results remains a moot point.

The sole reliance by the employer on unspecific polygraph results is insufficient to discharge the onus in terms of section 192 Labour Relations Act 66 of 1995 to prove that the dismissal was fair. To discharge this onus, the test of a balance of probabilities is used. To only present polygraph evidence is not enough to show that the dismissal was fair because there is no corroborating evidence.

Abide by the rules

Polygraph testing can be used, provided that you abide by the rules.

  • Try to get the employees consent. Preferably, you should get written consent before doing the test.
  • Use an expert or a qualified person to conduct the tests using accepted procedures.
  • Ensure that the subject is physically and mentally fit.
  • Explain the process to the subject.
  • The expert must testify about his/her findings.



It is best to get an employee’s consent to undergo a polygraph test because a polygraph test may potentially infringe two constitutional rights of the employee:

  1. The right to privacy.
  2. The right not to incriminate oneself – section (35) (3).

However, courts support the view that refusing to undergo the polygraph test can amount to a breach of contract, or even insubordination.

Case 3

In the case of Nyathi v Special Investigating Unit 2011 JOL 27537 LC the Labour Court upheld the employer’s argument that the employee’s refusal to undergo a polygraph test in relation to alleged misconduct was a material breach of her contract of employment.

The employer was entitled to accept such refusal and terminate the contract for these reasons.

In this case, the employee was contractually bound to undergo a polygraph test. In terms of her contract, the court found that the contractual obligation was reasonable, as long as it was applied reasonably. In this instance the employer’s organisation was responsible for investigating corruption in Government and State Institutions. Such a workplace requires utmost integrity from its employees.

Case 4

In another case, Gemalto South Africa (Pty)(Ltd) V CEPPWAWU obo Louw and others (JA54/14,27 August 2015) LAC, the union stated its unwillingness for its members to undergo polygraph tests.

After losses of about R50-million had been incurred by the employer’s client, the employer asked for its employees to be tested.

Most of the employees’ contracts contained clauses that required the employees to agree to polygraph testing but, in other instances, the employer had not included such clauses in the employees’ contracts.

The Commissioner at the CCMA found that there was no reason to treat the employees differently – including the employees whose contracts did not contain the said clauses.

On Appeal, the Labour Court later ruled that the refusal to submit to the polygraph test amounted to an act of insubordination.

Progressive approach 

Thus, it can be deduced that courts are moving towards a more progressive approach towards the use of polygraph test however, convincing reasons must be given in order to conduct polygraph tests.

The general trend at the CCMA is that polygraph evidence will be allowed on the following basis:

The CCMA must accept the polygraph examiner as an expert witness and test his/her evidence for reliability. The duty of the commissioner is to determine the admissibility and reliability of the evidence. The commissioner must not interpret the test as implying guilt, but he/she may regard it as an aggravating factor, especially where there is other evidence of misconduct.

In other words, polygraph test results, when used on their own, are not a basis for a finding of guilt. It can be used only in support of other evidence.

Case 5

In the case of Metal and Electrical Workers Union of SA on behalf of Mbonambi and S Bruce CC (MEKN855-14/5/2005) an employee was dismissed after being found guilty of stealing money and a cell phone. He was the only one of 11 employees tested by a polygraph examiner whose answers indicated deception.

The Arbitrator followed previous tribunals and held that the outcome of polygraph tests may be taken into account when there are other grounds for believing the employee had been dishonest.

In the above-mentioned case, the ‘other grounds’ were that a witness had identified the employee as being at the scene of the theft at the time theft took place. The Arbitrator also found the employee’s testimony to be inconsistent and dishonest. He admitted the polygraph evidence because it was relevant, and on a balance of probability, he found the employee guilty of theft.

Specific incidents

Instances where employers are permitted to use the polygraph test to investigate specific incidents are:

  • Employees had access to the property, which is the subject of the investigation.
  • There is a reasonable suspicion that the employee was involved in the incident.
  • There has been economic loss or injury to the employer’s business such as theft of company property.
  • The employer is combating dishonesty in positions of trust.
  • The employer is combating serious alcohol, illegal drugs or narcotics abuse and fraudulent behaviour within the company.
  • The employer is combating deliberate falsification of documents and lies regarding the true identity of the people involved.

Please note that polygraph testing may be used as a tool when investigating dishonesty. You should not take disciplinary action based solely on a failed polygraph test unless you have corroborative evidence to support it.

A commissioner or judge will attach very little weight to polygraph test results if there is no supporting evidence because a polygraph test does not record lies.

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