As Brett has said, is there any play in the shaft? Also, have you followed the leak up to see if you can see where it's coming from? I know that's not easy when the cars wet, but you should be able to tell hte difference between water and tranny oil.
If it is the seal then it's not a massivly expensive thing to fix, and shouldn't cost more the £60 all in.
ive not had a time to investigate it a bit more. i think ill need to clean the surrounding area, check shaft and try and find the source. ive got springs, taylored mats and new bulbs and leds on they way so this is the last thing i need lol.
think ive pinpointed it to a seal leak as the drive shaft goes into the gearbox. the oil is making its way down then trickling along a little the where it can be seen in the photo.may also explain why it leaks when driving.
Get that replaced then dude. When you're getting it done though, make sure that the garage you're using only use Honda tranny fluid. Most 'immitation' fluids just aren't as good.