2002 Citroen Saxo oil leak from front drivers side wheel gater

If you are sure that's where the oil is coming from double check the gaitor for splits and look at the securing clips to make sure they are tight. There really isn't any other way for grease/oil to get out.

is it running down from shock absorber ? or brake calliper ? or as suggested the inner ( drive shaft end clip on CV boot loose, the grease does tend to go a bit runnier if it done a few miles ! but only suggestions !!!