Employers cannot rely solely on polygraph reports in disciplinary proceedings

Employers are often of the opinion that they can rely only on the results of a failed polygraph test when instituting disciplinary action to prove their case against an employee. This is not the case and employers should be aware of the dire consequences thereof. 

There is no specific legislation regulating the use of polygraph tests (also known as a ‘lie detector test’) and therefore we have to rely on case law in this regard.  Case law is clear that an employer’s reliance solely on polygraph tests when dismissing an employee without presenting evidence corroborating the test results is not justified, and an employer may be faced with a maximum compensation award or even retrospective reinstatement. 

In DHL Supply Chain (Pty) Ltd and National Bargaining Council for the Road and Freight Industry, R Dube and Masinga [2014] ZALAC, the Court held that polygraph evidence may only be relied upon if the party relying on it adduces expert evidence to prove its reliability as well as the accuracy of its use and application in a given case. The inference drawn from the failure of a polygraph test is only useful in determining probabilities. 

A polygraph test only indicates deception in an employee’s answer and is considered as circumstantial evidence. It does not prove an employee’s guilt. Relying only on the results of a polygraph test does not discharge the onus of proof on the employer and the employer will have to present supporting evidence to prove the misconduct.

Polygraph testing is completely voluntary and an employee cannot be compelled to undergo a polygraph test. The only exception to this is if the employee agreed to it in terms of a collective agreement or agreed to it in his or her contract of employment or internal disciplinary code of the employer.  Employers must make sure that a written agreement exists explicitly stating that the employee consents to undergo a polygraph test. 

In the recent case of Goldplat Recovery (Pty) Ltd v Commission for Conciliation, Mediation & Arbitration and Others (JR 488/2019) [2021] ZALCJHB 48 (3 February 2021), an employee was dismissed for being in possession of gold. The gold came from a restricted area and an employee stated that there was a smuggling syndicate but refused to disclose the identity of the others. Another employee who had access to the area did a polygraph test and failed. This employee was then charged and ultimately dismissed. 

The disgruntled employee referred an unfair dismissal dispute to the CCMA and the Commissioner found that other employees also had access to the restricted area and that the assumption that the employee was guilty for failing his polygraph was speculation.  There was no evidence that he was the only employee who failed the test. The Commissioner further held that the employer failed to lead expert evidence to deal with the polygraph and found in favour of the employee and awarded maximum compensation. 

The employer was not happy with the award and applied to the Labour Court to review the outcome. The Labour Court agreed that the employer failed to call an expert witness and relied solely on the polygraph test result to establish the employee’s guilt. The Labour Court found that there was more than one reasonable inference that could be drawn from the evidence and therefore upheld the CCMA’s findings and dismissed the review application with costs. 

Employers must be careful to rely solely on the results of polygraph tests when instituting disciplinary action and subsequently dismissing an employee who fails the test. It is clear from the case law above that the sole reliance on a polygraph test will be insufficient to prove that an employee is guilty of misconduct. 

Do not hesitate to contact Invictus should you require assistance to ensure that your contracts of employment and disciplinary codes make provision for employees to undergo polygraph tests. 

Contact Invictus Group on 0861 737 263 for us to assist you.