Without the requested information, I can only provide you with general information, which hopefully will still be useful to you. Employers have the right to have a search policy in the workplace, which allows them to request that employees consent to being searched.
In fact, it is not illegal to search a car, even if there is no reasonable suspicion of wrongdoing. That may eb the case if the police are involved, but there are no such rules foe employers. The same applies for personal searches – by law, no reasonable suspicion is necessary and the employer can have whatever policy they want, be it random searches, blanket policy for all to be searched, etc.
The only legal requirement is that the person being searched consents to it. An employee cannot be forced to be searched, otherwise doing so without consent could constitute the criminal offences of assault or battery. Saying that, if the employee unreasonably refuses to be searched when the employer has reasonable grounds for doing so under a proper workplace search policy, or genuine and reasonable suspicions, they may face disciplinary action. Based on the investigation and the employer’s belief of their guilt, it could even result in dismissal. Legally, the employer is able to make a decision based on the evidence that is available to them following a reasonable investigation so if that suggests that the employee may have done something wrong, in the absence of a search and an unreasonable refusal, disciplinary action can be taken.