Removing a tea/coffee stain from a leather sofa?

[6thElement]

Unfortunately one of my sofas seems to have aquired a tea or coffee stain down the side of it. It's a light sand coloured leather and nothing I've tried seems to help shift the run marks. Anyone got any bright ideas?

 

[6thElement]

I've tried most of the kitchen/bathroom cleaner "stuff" and they're having no effect :/