Have noticed a leak from under the engine bay, drivers side. the casing of the engine seems to be soaked in whatever it is....have attached a photo here. Anyone have any ideas?

 

have you put something under the car to catch some drips to see what color/feel the fluid has? keep an eye on your fluid levels - most likely its either coolant or motor oil but you'd need to clean up the engine then see if you can find the source of any fresh leakage. If its engine oil, I do a test of the PCV system - a clogged PCV can push oil out of the cam seals and a few other places...

 

When you get around to trying to locate the source of the leak, always start where it's wettest and work up... if necessary, use some engine cleaner and get the entire engine compartment as clean as possible (where it's oily now, anyway...) and it'll be a lot easier to spot the leak.

Judging from the photo, it shouldn't be TOO hard to spot the source of that leak!