Citroen zx noise that disappears when treading clutch

Hello, I have a Citroen ZX 1.9D which for a few days and especially cold makes a squeak similar to the one that makes a belt and said noise disappears when the clutch steps on, so that the clutch floor floor and the noise disappears and when the clutch is released it no longer does it again until the car is cold again, what can it be? Thank you.