[kleiba]

From an employer's perspective, this is fine because you don't want to lose more paid work hours without any return.

From the employee's perspective, it's a different story of course. The point of vacation is that you can recuperate from work stress and get some energy back, so that you stay healthy and can deliver good work. I doubt very much that this goal can be reached when the reason for your time off work is that you're under investigation. For instance, I don't expect most cops to fly to Vegas to party during such a time.