Grinding Noise vRS

looking for a little advice if possible, my cars developed a rather scary grinding noise from the engine bay..

its quite high pitched so hard to place as it is a little sore on the ears trying to pinpoint the exact location.

i think its coming from the Aux belt area, possibly alternator. its a horrific sound and only seems to appear as i arrive home from work, so seems to develop when the car is warm. never notice anything in the mornings or even when i have been on other journeys, this is the second time i've heard it in 3 days.

tried spraying a little wd40 at the alternator when it was running to see if the noise went away but made no difference.

a new Aux belt was fitted earlier this year so it shouldnt be the belt although this is not a belt noise but could be something that the belt drives

has this happened to anyone else or got a clue what it could be?

very worried that something is going to seize or break when i am driving, moneys a little tight at the moment and i rely on my car for work purposes.