We recently came across a number of faulty moulded 3 core power cords (kettle leads). There was no measureable earth path i.e. earth resistance greater than 20 ohms. It is of particular concern that these were found within schools.
We have contacted the chinese manufacturer who are investigating the matter. One point raised by them is that they are aware of a number of faulty counterfeit cords on the market from China, both here and in mainland Europe.
It seems bizare that the chinese are counterfeiting their own products (how much cheaper can they get), but keep an eye out for them.