"There are frequent, small regressions in New Zealand in media freedom, and the important thing here is that media freedom is not on behalf of the media, it's not for media companies - it's freedom of expression and freedom of information on the public's behalf.
"To see a country like ours being viewed by an external outfit like Reporters Without Borders as going backwards is very disappointing."
Murphy said any detached view of New Zealand media freedom would have looked at things such as the police investigation into the teapot tapes.
The teapot tapes saga resurfaced yesterday when a leaked recording of the pre-election conversation between Prime Minister John Key and Epsom MP John Banks was posted online anonymously.
The original recording was made when freelance cameraman Bradley Ambrose left a microphone on a table during the publicity stunt at a cafe.
Ambrose, who claims the recording was inadvertent, passed it on to the Herald on Sunday, which approached Mr Key seeking to publish its contents.
Mr Key declined and laid a complaint with police, leading to search warrants being executed at the newsrooms of four media outfits.
Murphy said the decision to call in the police "would not have played well" with those assessing media freedoms. He also cited the Government's Search and Surveillance Bill.
Murphy said erosions to media freedoms were creeping and incremental, and the public did not generally realise until there was "a reminder like this".