I would have no hesitation in speaking with the builder and letting him know that it will be reported to the police.
You’re not accusing him personally, but providing him with information that he needs about his workforce.
It may mean a delay in the building work whilst he “rests” anyone in his team.
I’m sure that you will have taken details of his insurers and could report the theft to them (which the builder will want to avoid).
"I know there are people worse off then me"
Interview with the economist billionaires fear: this is how we get a wealth tax


