KavaKava on the liver

Hi I have been hearing more about the Kava Kava Root and was wondering if you had any concrete information on it. When researching KavaKava Roots Ive come across a lot of references explaining how there is a chance of liver damage in one way or another.  Someone I was talking to said that a lot of the websites online will say that but its only dangerous when parts of the leaf are digested too. Do you know any turth behind any of these??? Thank You!