2007 Petrol vRS with hanging revs

Hi all, been noticing this happening more frequently with my Octavia recently...

Happens most often when approaching a junction where I need to stop, as I approach I drop to 2nd, then put the car out of gear, the revs drop down but seem to get stuck at around 2000 for between one and several seconds before dropping down to normal idle

It will also sometimes do this if the car is in gear causing a swift application of the brakes to get her slowed down...

I've searched the forums, but didn't find much that seemed applicable to this situation, if anyone has any bright ideas where to start looking it would be much appreciated 🙂