The CAA is a diverse group of small specialist units, many of whom investigate things. Can you be more specific?
ARE have real investigators (ex Police)
FOD have inspectors, some of whom are said to be Plod like.
SIDD have investigators who do a darn good job imho.
The ladies doing the CAA Travel Audit at departure lounges could be said to be investigating. Are you a size 10/12 or a larger figure?
Perhaps worth thinking about how to pose questions before stepping up to the job application mark?
Sir George Cayley