Freelander 1, 2.0Di from 2000 losing power and speed climbing.

Hi all,
I have a Freelander 1, 2.0Di L-series from the year 2000, and it seems to be losing power on the climbs, also, it can no longer reach higher than 150kms/hr.
I had look at and around the engine and noticed i have a bit of an oil leakage from the turbo. could this be the problem?
I would appreciate any help!
Thanks.

Replace crankcase breather as a matter of urgency and check all hoses for splits, collapsing.