Sean Hannity discussing the post-debate fallout on his program Tuesday night. Fox News A Fox News executive sent a memo to television producers and the politics team on Tuesday afternoon reminding employees that unscientific online polls "do not meet our editorial standards."

Dana Blanton, the vice president of public-opinion research at Fox News, explained in the memo obtained by Business Insider that "online 'polls' like the one on Drudge, Time, etc. where people can opt-in or self-select … are really just for fun."

"As most of the publications themselves clearly state, the sample obviously can't be representative of the electorate because they only reflect the views of those Internet users who have chosen to participate," Blanton wrote.

As the Fox News executive pointed out, users who participate in such polls must have internet access, be online at the time of the poll, be fans of the website in question, and self-select to participate.

"Another problem — we know some campaigns/groups of supporters encourage people to vote in online polls and flood the results," she wrote. "These quickie click items do not meet our editorial standards."

At least three Fox News hosts cited unscientific online polls in the hours after Monday night's presidential debate to suggest Donald Trump emerged as the winner of the political showdown.

Trump had come out ahead in a slew of unscientific polls, or polls in which the sample of participants did not accurately reflect the sample of viewers who watched the debate. Such polls are almost always discounted by professional pollsters and analysts.

The only scientific survey conducted in the debate's immediate aftermath was the CNN/ORC instant poll, which showed that viewers thought Hillary Clinton handily defeated Trump. Respondents to a Morning Consult poll released Wednesday also said, 49% to 26%, that Clinton bested Trump in the debate.

"News networks and other organizations go to great effort and rigor to conduct scientific polls — for good reason," Blanton wrote in the memo. "They know quick vote items posted on the web are nonsense, not true measures of public opinion."

Blanton further pointed out that instant/snap polls "are DIFFERENT" from online polls but "can be used on air — with caution."

"Fox News policy is to focus on non-partisan telephone polls (with both landlines & cellphones) that use live interviewers, and random digit-dial sampling techniques — a methodology that enables everyone an equal chance of being interviewed," Blanton said.

Since the memo was issued, however, some Fox hosts have continued to cite the online polls, often failing to even note such polls were unscientific and conducted over the internet.

Host Sean Hannity, who has led the charge citing the unscientific polls, continued to do so Tuesday night, after the memo went out.

"You've got this list of polls, Donald Trump wins," he said during on segment. "You watch TV, Hillary Clinton wins."

Brian Kilmeade, a host of "Fox & Friends," also referred to the online polls during an interview with a Trump official Wednesday morning.

"The online polls show you guys won in overwhelming margins," he said, a comment for which Trump later thanked him on Twitter.

A representative for Fox News noted both Hannity and Kilmeade are hosts in the network’s lineup of opinion programming. The representative also pointed out that Hannity has publicly disclosed that he has endorsed Trump.

Hannity, in fact, stirred controversy last week when he participated in an official web ad for the Republican presidential nominee. A Fox News representative later told The Washington Post the person had "no knowledge" he "was participating in this" and that "he will not be doing anything along these lines for the remainder of the election."

Trump frequently touted online polls in the aftermath of the GOP debates to argue that he won. After the Monday face-off with Clinton, he continued the pattern, repeatedly touting polls that supporters had flooded to designate him the winner.

Not only were those polls contrary to the scientific surveys conducted, but focus groups also overwhelmingly selected Clinton as the debate winner.

Editor's note: This story has been updated to reflect comment from a Fox News spokesperson.