If I use Japan voice pack,does Riot ban me?

No, I'm using it for Ahri.

No. It's very common to use a language pack your region doesn't have.

Thats what im asking myself too... i really want to use it... but i don't want to risk any ban

A friend of mine said that his friend has been banned for using the japanese voiceover... as he changed gamefiles

I want to know if this is really banable now... as i really like the japanese voiceover most....

And please... just answering with "no its not illegal as i use it and do not have been banned" doesen't help at all :) leave some sources please