This is the very reason why, when people who don't have cats think if they see a cat around their back door it's a stray and perfectly acceptable to feed it.
It pains me when I read of this. They think they're doing a kindness without realising that the cat will take food from anyone if hungry and will continue to hang around.
If they want to do a kindness, dont feed it and let the local Vet know, now that would be far kinder.
i feel for you daffy. I have panicked when my cat has gone missing for less than a day as he is such a creature of habit, i can't imagine what you're going through.
I'll bet someone has unwittingly started to feed him. If that's the case he will make his way back to you. Fingers,toes and everything else crossed for you.