Police will not lay charges against Radio Live over its decision to broadcast an hour-long programme hosted by Prime Minister John Key weeks before the 2011 election.
Radio Live hosted "The PM's Hour" on September 30 last year.
It featured Mr Key interviewing famous guests including Sir Peter Jackson and Richard Branson in what was billed a politics-free hour.
The show was referred to police by the Electoral Commission after it found breaches of election rules.
Detective Superintendent Rod Drew said police had considered the findings of the Broadcasting Standards Authority and the Electoral Commission before making a call on prosecution.