Animal rights activist group SAFE has denied it's behind the hidden camera. Executive director Hans Kriek said it has nothing to do with his organisation.
Mr Kriek said the first time they had heard about the camera was when media rang him to speak about the issue.
"I can tell you in this case this has nothing to do with SAFE," he said.
The Ministry for Primary Industries has also released a statement saying it has nothing to do with the hidden camera.
MPI Waikato Compliance Manager Brendon Mikkelsen said if there are cameras in dairy sheds they are not MPI cameras and they support a police investigation.