HI all,
Thank you all for the helpful advice. I've had a bit of a virus this week and haven't had chance to do anything about it.
The floor is a vynil like tile, but thick ones with a patteren impressed into them. This is where the staining is worst and some of the impressions are only the size of a pin prick. I will try some of the suggestions here over the weekend and see what happens. I might even try putting a UV light above it as sunlight is supposed to get rid of these stains, but I wonder how much light it would need to be effective.
Thanks again.
KP(V)