Sounds like a laying worker to me or, as mentioned, an improperly mated queen. Although drastic my initial thought would be to do the old 'conquer and divide' take the old box away from the original site and shake everything out on the ground. Put a box back in the original hives location and, as you brush down each brood frame, place it back in the box in the original location - the field bees and drones will return to the hive but 'hopefully' the laying worker/poorly mated queen wont... in any case have a good scour through the bees left to look for a queen. Make sure you then leave the original hive queenless for a period of time (4-6hrs) and then introduce a new queen