The police file on the "Teapot Tapes'' says NZ First leader Winston Peters would have been considered as a target for prosecution if charges were laid against the cameraman who recorded the pre-election conversation.
It says Mr Peters' actions repeating details of the recorded conversation meant he would be in the frame - if charges against Bradley Ambrose went ahead.
The recording was made when John Key met Act leader John Banks in a show of pre-election support. It has never been broadcast by media, although Mr Key went to police alleging the recording happened in a ``News of the World''-style operation run by the Herald on Sunday and Mr Ambrose. The claim was denied by both.
After investigating, police said no charges would be laid although they believed Mr Ambrose's actions were unlawful. Mr Key had rejected charging Mr Ambrose after receiving a ``letter of regret'' from the camera operator.
The Herald has seen a section of the police file showing Mr Peters was being considered for criminal investigation - but only if Mr Ambrose was charged. The link to Mr Peters was his pre-election drip-feeding of portions of the tape.