The final Des Moines Register/CNN/Mediacom Iowa Poll will not be released as planned Saturday night.

A statement released by the Des Moines Register said: "Nothing is more important to the Register and its polling partners than the integrity of the Iowa Poll. Today, a respondent raised an issue with the way the survey was administered, which could have compromised the results of the poll. It appears a candidate's name was omitted in at least one interview in which the respondent was asked to name their preferred candidate."

The Register said it believes it was a singular error in an isolated incident, but it has not confirmed that yet.

"The Register has published the Iowa Poll for 76 years and it is considered the gold standard in political polling. Selzer & Co., which conducts the poll, is recognized for its excellence in polling. It is imperative whenever an Iowa Poll (is done) that there is confidence that the data is accurately reflects Iowans' opinions."

A tweet by Jonathan Martin, national correspondent with the New York Times said, "The @DMRegister is weighing whether to release their (Iowa Poll) as planned tonight after @PeteButtigieg camp complained that his name was left off at least one survey questionnaire."

On Sunday, the Iowa Poll put Sen. Bernie Sanders in the lead for the Iowa Democratic presidential candidate at 26%. Former Vice President Joe Biden was in a close second at 25%. Mayor Pete Buttigieg took third, polling at 22% with Iowans. Sen. Elizabeth Warren had 15%, and Sen. Amy Klobuchar had 7%.

The margin of error for Sunday's poll was 3.9 percentage points.