15p td5 still getting diesal in the oil

Im runing out of ideas .starts runs fine but oil stick is raiseing with oil
ive removed injectors .and replaced with geniune seals and copper sealing washers and torqued to spec
Problem still here
I bit the bullet and bought a brand new clyinder head
bolts.gaskets and another set of injector seal kit.
Went for a run and problem is still there ...
any idea what else maybe causeing the fault ?

read somwere the other day that it could be the lift pump faulty leaking diesel through into the engine