If coming from the area of the flywheel, try removing the l/h engine cover and fitting a new gasket? Before fitting, check that the mating surfaces are flat. If not, smear a SMALL layer of sealant or similar on the mating surfaces prior to fitting the new gasket.
Do not apply to much gasket, do not pipe it on like toothpaste, as per the picture on one well known brand. If you do, you'll end up with the excess sealant inside your engine, blocking oilways etc, leading to much woe & trauma......
New 0' ring should cure the oil filter cover leak. Treat as above if req'd.
Remember to clean around any cover prior to removing it.