potential gasket issue

[Wain]

I have an MX5 engine in my car, but there is a small oil leak coming from the front side of the block. Its not enough to leave a puddle on the floor, but it is damp right down to the crank position sensor.
I have attached an image of the side of the engine with the manifold off, above the water pump. Please advise your thoughts and if its a head gasket failure. The engine runs fine and i mentioned it to a mechanic a few months ago but he advised it could just be old. I know its not though as the crank position sensor got replaced a few months ago and is now damp with oil.