Landrover Freelander 2 - back end noise - Pete D.

I have a lot of rumbling/ Whining noise coming from the back end of my 2009 Freelander 2- especially on the motor way. Any ideas on what this could be?

Landrover Freelander 2 - back end noise - focussed

Possible/impending failure of rear differential? see here

http://www.honestjohn.co.uk/carbycar/land-rover/freelander-2-2006/?section=bad