Las Vegas, Nevada - NFL commissioner Roger Goodell dismissed conspiracy theories surrounding Taylor Swift as "nonsense" on Monday as the final countdown to this week's Super Bowl got under way in Las Vegas.

Pop icon Swift's burgeoning romance with Kansas City Chiefs star Travis Kelce has been cited by right-wing critics as evidence of a plot to rig the Super Bowl and help get US President Joe Biden reelected.

The bizarre theories have characterized Kelce and Swift's relationship as a deep-state psychological operation, designed to tip this year's presidential election in Biden's favor, with Fox News asking in a recent discussion: "Is Taylor Swift a Pentagon asset?"

Mike Crispi, a pro-Donald Trump broadcast personality, meanwhile declared recently: "EVERYONE knows Taylor Swift and Travis Kelce is fake and the Super Bowl is rigged. You’re a whacko at this point if you DON’T believe it."

But National Football League chief Goodell was having none of it as he addressed reporters in the depths of Allegiant Stadium on Monday ahead of next Sunday's Super Bowl showpiece between Kansas City and the San Francisco 49ers.

"Anybody in society in a public position is subject to criticism," Goodell said of the conspiracy theories.

"But I think the idea that this is within a script, this is pre-planned, is just nonsense," Goodell said. "It's frankly not even worth talking about."

For one thing, Goodell noted wryly: "I'm not that good a scripter."

Goodell, though, was effusive about the impact Swift's relationship with Kelce has had on America's favorite sport.

Ever since Swift began attending Kelce's games for Kansas City earlier this season, television audience numbers have surged, with ratings showing a boost among female viewers.

The Chiefs' playoff win over the Baltimore Ravens was the most watched AFC Championship game in history.

"She's a remarkable performer," Goodell said of Swift. "She's the best of the best."

"The Taylor Swift effect is all positive. Travis and Taylor are wonderful young people. They seem very happy. She knows great entertainment, and I think that's why she loves NFL football. It's great to have her part of it."

"Obviously, it creates buzz. So another group of young fans, particularly young women, that are interested in saying, 'Why should we watch this game? Why is (Taylor) interested in this game?'"

On Sunday, Swift made Grammys history by winning her fourth Album of the Year prize, the most of any performer.