avoiding products manufactured with the use of human slave labour

[Rupert McCallum]

I'm seeking information about how one can take steps to ensure that the products one buys are not manufactured with the use of human slave labour. (This would presumably be part of what is required in order to be vegan.) In particular, I'm given to understand that coffee can be a problem in this regard. It seems to be a bit difficult to find useful information about the matter. I suppose if you took care to buy only Fairtrade coffee then you could be pretty confident that the use of human slave labour was not involved in its production, but apparently there's a substantial controversy about whether Fairtrade certification is helpful to poor farmers or possibly even positively harmful to them. I'd welcome any guidance about how best to proceed in this matter.