If it is a F&P smartdrive it will almost certainly be the drain hose. Due to the stupid design of the holding bracket this hose often slips out of the bracket & rubs on the sharp edge of cabinet. Look where the hose goes through the cabinet wall and bend the hose to see if there are any tiny pin holes. Fill the hole with some silicone & wrap some tape tightly over the top of the silicone. The only other place that leaks is the inlet hoses but you should be able to see water dripping off those hoses quite easily.
Lincoln Appliance NZ, September 2009