Quote Originally Posted by trentrockport
Apart from trimming dead leaves they don't get touched. Similarly, they haven't been moved more than a few centimetres here and there. I have to ask myself if there are other cultivators in the area who are either intentionally growing males for seed or have accidentally allowed males to emit pollen. Should this be a concern? If so, what steps can be taken to prevent such pollination?
Nice thought, but likely it's stemming from your growroom. A few of the strains I intentionally stress to fem seeds, throw-out the nanners in the middle of the buds. (the nanners don't always grow from the nodes of stressed females)

Also, the pollen can last for a couple of weeks. Did you grow-out a male in the recent past, and not clean-up afterwards? (residual pollen still infecting the ladies?)