Police in New Zealand have banned fans from wearing Borat's skimpy one-piece bathing suit to a rugby tournament because they want to protect innocent children.

Police turned a blind eye to the dozens of men who donned the distinctive high-riding neon green swimsuit last year but say they will crack down at the world rugby Sevens event in Wellington this year.

"It's a family event and there will be children there," an officer said on New Zealand television today. He appealed to fans to have "a sense of decency."

The Wellington round of the Sevens traditionally attracts thousands of fans who don all kinds of fancy dress.

But anyone who turned up in the swimsuit made famous by British comedian Sacha Baron Cohen in his hit movie Borat will be turned away, police said.