Peugeot 206 screaching noise when driving above 40mph

Could possibly be water pump on the way out or a tensioner beginning to lock up.
Needs to checked ASAP, as it could be costly if something does lock up...

Or fan belt issue,tensioner may have collapsed.

Thankyou for your replies. I have it booked in to be checked out later this week. Do you think its safe to drive until then? I drove it today & i only heard it once. Seems if i stay below 40mph its ok.

Would not go driving it any great distance until issue is resolved in case engine damage occurs.

I have taken my car to 2 different garages this morning. Problem is there's no-where locally you can drive above 40mph so they couldnt hear it. Had a look over the engine, couldnt see anything obvious. But they did say i need front pads & discs. Could it have been this making the screeching? Wouldn't it screech at any speed or when i brake?

It is possible front pads worn could cause a noise but you would think the noise would be there all the time and not above a certain speed ,I wonder to what percentage of wear is left in the pads,as if it need,s discs running the pads down to the minimum will do no further harm. As I do not think this is the noise concern you mentioned previously.Would ask the garage to test it with yourself in order to catch the correct fault.

I ended up trying another garage who said it was just my break pads which needed replacing, not the discs. I have now had them done but the screech is still there. Also, I noticed last night that the engine was overheating. When I got home, I topped up the water, only needed about half a litre so I assume I don't have a leak anywhere. I was only on the road this morning for about 5 minutes, only doing around 30mph and I didn't get stuck in traffic. I had my heater on full, as I heard that this can keep the engine cool. The temp gauge went above 90 (usually stays at 80) then I think the fan kicked in. Does this also suggest a problem with the water pump? Or something else? The garages I seem to be going to are either not very good, or the problem really isn't very obvious!