Turbo diesel sluggish at higher revs

[Down Towne]

I have a April 2004 3L turbo diesel patrol wagon and over the past few days it has become very sluggish at ghigher revs as thought the turbo is not cutting in. It has been recently serviced and all of the filters have been changed so it isn't starving for fuel or air.

Dose anyone know whether there are any sensors that could be causing this or I am I going to have to start looking at the turbo??

Cheers