diesel leak

hi ive just got home and had the heater on in my roomster and all the way home had a strong smell of what smelt like polish, on arriving home i popped the bonnett and in the dark i could see something was over the engine and on further investingation found it was diesel, i couldnt see were it was coming from as limited light until morning but any ideas would be appreciated, ps its a skoda roomster 1.4 tdi thank you