help needed identifying paving stone origin

Hello and apologies if our question is foolish. We are probably the smallest newspaper in the UK and a few years ago the local government replaced the town's pavements/sidewalks with new paving stones, supposedly from Yorkshire. Since then a large number of people have slipped on the stones, causing some serious injuries, and there are rumours that rather than being Yorkshire paving this is actually a cheaper product imported from Asia. Is there a simple test to determine the likely origin of this stone?
Thanks
Daniel Bennett
Editor