A complaint against The Rock radio station for a segment that saw the Prime Minister take part in an on-air "joke" about rape has been upheld.
In December John Key and the station came under fire after the PM agreed to get into a cage, and then was asked to pick up a bar of soap - a reference to rape in prison.
The Broadcasting Standards Authority says The Rock Morning Rumble show breached good taste and decency and responsible programme standards.
The stunt was a deliberate reference to prison rape.
MediaWorks has been ordered to pay $1000 to the Crown and make a statement on air.
"Sexual violence is a serious issue which affects some of the most vulnerable people in society, including those who are incarcerated," the Authority said in a statement.
It said the segment would have offended many people.
"This was not an off-the-cuff or fleeting joke made on the spur of the moment. Rather, the gathering and use of props such as soap, as well as quoting from the film Deliverance, in our view clearly required some forethought."
At the time Mr Key said he did not know what was going to happen in the segment before he took part, and did not pick up the rape connotation in the moment.