Are you sure its oil and not diesel or both. I chased my tail as it turned out to be both. There are lots of forum discussions just search TD5 oil leaks.
My recommendations would be:
a. Use UV oil trace first to pinpoint the leak, or as I did you may spend time and money for no good reason.
b. Likely leak areas back of rocker gasket near half moon seal, and a little sealant and new gasket, while your in there I would change the injector loom, as it will start leaking into ECU connector.
c. Front cam inspection bung, simply replace or add a little blue seal.
d. Mine turned out to be a combination of the diesel regulator mixed in with a shot crank shaft seal, not a cheap or easy fix.
All the Best Michael
You do not own your Land Rover, you just maintain it for future generations.