It's power is from outside of litecoin network, because of him the litecoin diffculty is increasing heavily and network total hash is above 30GH/s now.

As long as we know, no one can make this big farm of gpu, it should be something else.

Maybe a bitcoin mining pool that pointed to litecoin and all of it's users changed their cgminer settings as well. (BTW, if this assumption would be correct, we should know that pool in forums that converted from bitcoin to litecoin with all of its users, do you know any??)