The court ruling on lifting name suppression on Commodore Keating is an interesting read. Basically a visual recording device was found in the bathroom of the NZ Embassy in Washington. NZ Police had to be dispatched to Washington DC to investigate.
The Police found his computer had been used to install driver software for the camera and further his DNA was found on the SD card in the camera.
Without prejudging any defence, I have to say that is pretty difficult evidence to challenge.
If it does go to a defended hearing, I imagine huge media interest.