oil dripping from turbo

[Jimmy_GTT]

I have a T25 (tomcat with 360 bearing) which is dripping some oil to the gearbox.
First I've thought it is the oil return so changed the sealing. But not.
It seems as oil is dripping from the turbine housing. The screw at the bottom has oil on it.
Turbo has been checked by a specialist who has made it before. He has told that everything was fine. But he has changed a sealing at the back (to some oversized one) to be sure.
Now turbo is fitted back again to the car but still dripping oil (seems worse than before) and also has some puff of smoke.
I have changed the whole oil returning pipe till the sump.
I have modified the crank ventillation system as suggested, but all the same.
I haven't had any of these problems with my previous T2/T25.

Is there anything I can check on my car? Or is it definitely the turbo?

The oil feed pipe is standard one. I've used it with my previous turbos also.

Thanks

[Chunk]

Strange.. could the oil be dripping from the feed?

[Nottswoody]

Always has done it on mine bud I just wipe it up I know it's not an answer but I gave up looking what it could be along time ago.. But if you find out let me know :)

[Ashy]

Its usualy the rear seal on the turbo, its like a little piston ring, when you put it back in you need to make sure the gap is at the top to prevent it leaking.