Leak from filter in engine bay

Good evening I am new to the forum and new to the landy world as it's my girlfriends car,when removing the egr valve to clean out and do the egr valve delete I have noticed that there seems to be a lot of oil all round the area of what I assume is some sort of filter and also smells of diesel can I replace this part or is there any mods I can do to remove it cheers guys

welcome, should have dropped a line into the introduce yourself first. Guaranteed responce.. Did you get it cured?