Copyright infringement | Music stolen

[ssl_ambition]

I did a production for an established artist. After a disput the negotiations failed. Now I found out that my audio tracks has been re-arranged and released on purpose. Of course this is a copyright infringement but some parts got changed. It`s like some one makes a sculpture and another person sculpts it to a different shape. But the end result obviously still contains similar sounding elements. There is written material which prove the case but does anyone know some tips how to prove that he started from my production. Of course the case is processed by an attorney`s office and my track was copyright registered. But knowledge is power and even it`s clear that the started with my content, I need to prove exactly this. I`m thankful for every one that can support me with some knowledge (I can`t release details yet.)

Thanks!