Really Annoying Squeak

After noon guys,

yesterday i noticed that my car was squeaking from the front and was getting faster as i drove faster and gets louder when i break. so i thought it must be the breaks but the pads and discs are all fine took to a mate and he checked them as well and he is a stumped as the pads discs and callipers are all fine.

any ideas???

oh and it only happens if I've been driving for about half hour or so.

cheers guys

Mike