High pitched whining from dash

Hi, I've got a Superb II 170 TDi Elegance from late 2009. Over the last 5-6 months there has been a very irritating high pitched intermittent whine coming from inside the dash somewhere, which is becoming more frequent. I'm guessing it's not the climate control or ICE system because the noise continues with these turned off. It even continues with the engine turned off.

I've been to my local garage who hadn't come across it before so they sent a request to Skoda to see if they had seen it but no joy. One of the garage techs wondered if it might be a faulty cooling fan on the built in hard drive, similar to what you get on your laptop.

The car's going in to the garage in a couple of weeks time for investigation but I wondered if any other members has had (or is having) this issue as well?