Do I need to worry about this oil appearing?

[johnparker]

Hi all
My Dads mk9 1.2 tsi has a small amount of oil appearing on top of the engine. We have cleaned the area but in time it reappears.

In the centre of the photo is a black torx bolt head. You can just about see the oil in the recesses around it.
We dont really know what these parts are as we are both oldschool!
Just wondered if its anything to worry about.
Any advice greatly appreciated
John