Weird clump of wet looking fur on cats leg?

So my nearly 2 year old short hair male cat Zorro has a very good overall coat condition except for a clump of wet looking hair a little smaller than the size size of a american quarter on the upper inside of his left(from his point of view) leg.

 I've tried washing the area with warm soapy water, but after it dried it just went back to the same.

I then tried cleaning the area and around it with rubbing alcohol, not letting him lick it until it dried of coarse, but after it dried and he cleaned it it went back to the same.

Some observations, the fur around it looks totally normal and fluffy, both times while cleaning it i could not see any rash or the like on the skin beneath, also when cleaning it , especially with the alcohol , zorro showed no discomfort, it has absolutely no odour.

Its almost like there is something in the fur, but as he licks it so much i think its just wet from him cleaning the area.

So to look at it it looks like wet fur laying down in the direction of a cat licks the fur towards the paw, a little smaller than a quarter, 2 -3cm in diameter?, with no obvious rash or irritation on the skin beneath and no odour at all.

Going to take him to the vet but has anyone got any ideas what this could be?

Ill post some pictures the next time i get a chance.

Big thanks for any help.

Is this a recent development or do you think it has been there for a while?  It does sound like something is bothering him there  (pain, itching, etc), and not all things are visible to our eye.  A photo would be useful though.  It's good you are taking him to the vet as they will be able to have a better examination, and also check for any tiny mites that may be present.   I hope you find the answer and this is resolved easily for your cat.