A poll published on the Newshub website last year was found to have been manipulative by the Media Council, sparking calls for poll results to be better monitored.
On September 28 Newshub's AM Show activated a poll rating on Prime Minister Jacinda Ardern's performance at the United Nations.
Results were announced at the end of the show and found her performance was "great" 46 per cent, "good" 9 per cent, "average" 16 per cent and "poor" 29 per cent.
However, following the conclusion of the broadcast more votes were cast and by the end of the day the results of the poll had changed dramatically.
Four per cent of respondents had then changed their vote to "great", meanwhile, 95 per cent had voted Ardern's performance as "poor".
The Media Council then received a complaint from Jenny Kirk who was concerned about "poll fixing" as the results remained on the broadcasters page for days.
Kirk also raised concerns about unfairness, inaccuracy and lack of balance - she added the situation went "well beyond the standards of decency which New Zealanders expect from their media".
Until the complaint was received by Mediaworks' Standards Committee they were unaware about the altered results and believed the poll was manipulated.
The committee confirmed the poll had been artificially manipulated to the Media Council but said the manipulation only occurred after the broadcast.
Mediaworks subsequently removed the manipulated votes from the results and said while their polls are not scientific or "not necessarily political" in nature and often cover trivial topics.
However, the Media Council said while some of their polls are undoubtedly trivial of nature, this poll about Ardern and the UN was not.
"The manipulation of the data meant viewers were misled by information and Mediaworks failed to take prompt action," the council said.
"In all circumstances, but especially when manufacturing their own 'news', news media need to take special care to ensure they are not being manipulated to political ends.
"This will ensure the public can continue to have faith in the integrity of their mainstream news sources."
Kirk's complaint was upheld by the Media Council by a majority of 8:1, finding the manipulated results had been published for an unknown period.
Media Council member Tm Watkin dissented from the decision and noted some means of distinguishing scientific polls from self-selecting viewer polls would be welcome.
He was also of the view people should realise polls such as this were not to be taken seriously or viewed as scientific.
A spokesperson for Mediaworks said they accepted the findings from the Media Council: "We accept the findings, in particular, the dissenting view of Tim Watkin."