In reply to FranC:
If you need spares, base camp will stock the part you need. However I think a good service should fix it. The part leaking is where the pre-heat tube enters the bit where the jet injects the fuel vapour and mixes it with air. If you unscrew the bits you will find a removable part with a tiny hole in it, I think this whole assembly will just need cleaning and screwing back together.
Failing that, you may isolate what part might be damaged, in which case you can order replacements from base camp.