Follow the money
Large transactions like that don't go undetected by intelligence agencies round the world and all transactions will ultimately be traced to their destination even if they go through multiple fiscal paradises.
But we, mere peons, will never know for sure who really did it or where the money went. The truth will only transpire if those in the know have some interest in spelling it out to the world, but even then we'll never know if it's true or false.