Would doubt the owner would kill the bird mate, im sure they would be glad to see the bird again and yo kmnow of where it has been. Did thr r.p.r.a not give you a phone number for the owner? did you tell them you dont keep pigeons, and had no where to house the bird? they should contact owner straight away, Is there anyone near you that you have seen pigeons at?
thanks for being so helpful, im sure the bird and owner would appreciate, by the way, if the bird can fly and appears healthy i.e not to thin, it should make its way home if you take it away from your house, if it comes back you will have to get a shed, and we can sort you out with a few more to go with it :-) :-)