Hi,
When i press the clutch pedal down, there is a strange noise (rubbing sound possibly)
Once pedal is back up the noise stops.
No noise when driving.

There's some "rusty or muddy" looking water coming out of somewhere under the engine. (this vitara spent the last few months playing in the mud)

I've jetwashed the life out the underside to clean it up but wondered if this was maybe either a gasket split or a clutch bearing.

Sounds like your release bearing is knackered.

S4it in the release bearing

Release bearing as others have said, I believe its quite a common problem on vitaras and samurais.

Clutch free play needs to be adjusted, which would be done by replacing the rubber stopper.