I think they might be on dodgy ground with a physical search.
I've done staff searches in the past, and the most important thing I was taught was that I was not allowed to touch the staff or their belongings.
This might be useful.
www.darlingtons.com/blog/do-employers-have-rights-to-search-employees
If an employee or employees indicate they will agree to be searched, care should be taken in the way a search is conducted. The following are important considerations :-
The search should be conducted by a manager of the same gender as the employee and who has been suitably trained to carry out the search;
Before conducting the search, the manager should explain to the employee the reason for the search;
Obtain the employee’s consent prior to carrying out the search;
The search should be carried out in front of a witness;
Employees should not be asked to remove any clothing that would expose the employee’s underwear. If there is enough suspicion that a further search is required then the police should be called;
The search should not be conducted in the presence of other staff or members of the public as this could be embarrassing;
Except with compelling evidence of wrongdoing, a search policy, in general, should apply to and be enforced on all employees;
A search of employee’s property should be carried out with care and respect. The employee should be asked to empty things out first such as their pockets or the contents of their bags. If the employee’s property is damaged during a search then the employee may be able to claim it back from the employer particularly where there has been found to have been no misconduct;
A log should be kept of the search results, particularly where there has been misconduct; and
The log should be kept confidential and should be monitored by senior staff to ensure its randomness, reasonableness, fairness and consistency.
Ideally a search policy and the procedure should be set out in an employee handbook (if one exists) or be set out with the organisation’s other policies such as its disciplinary and grievance policy.
This is important so that everyone knows where they stand; not just the employees but also the managers carrying out the searches.