Is Polygraph Testing still a Legitimate Investigative Tool for Employers?

Employers often struggle to find direct evidence implicating employees in acts of misconduct. Polygraph testing is one of the tools used by employers as part of their investigations into misconduct.

Although our courts have recognised that polygraph test results have limited utility (on their own) in proving misconduct, a recent Labour Court judgment has recognised that where an employee has a contractual obligation to undergo a polygraph test, his/her refusal to do so may (in itself) constitute misconduct which may lead to disciplinary action and dismissal.

The issue was considered by the Labour Court in CCD Couriers v Maseko and others (delivered on 25 April 2024). It arose in the context of the discovery that a courier company's vehicle, which had new tyres, had those tyres removed and replaced with worn-out tyres. 

The employer, as part of its investigation, requested drivers who had used the vehicle to undergo a polygraph test. Mr Maseko refused to undergo the polygraph test despite his employment contract requiring him to do so.

He was charged with breaching his employment contract and insubordination for refusing the instruction to undergo the test.

The Labour Court found that he had committed the misconduct, which was a dismissable offence. 

The judgment underscores that polygraph testing remains a legitimate investigative tool for employers and that employees whose contracts require such testing may be held to those obligations and may face disciplinary action where they do not comply with them.