SANTA ANA, Calif. — Shaquille O’Neal swears by them. The Power Balance bracelet, he says, gives him a competitive edge on the court. It’s no gimmick, he says. It’s for real.

It may be for him, but Australian authorities say the California-based company behind the wildly popular wristbands and pendants has no business claiming that they improve balance, strength and flexibility.

And they even got Power Balance to admit it. The company wrote: “We admit that there is no credible scientific evidence that supports our claims.”

The company’s admission, however, hopped across the globe since its agreement with the Australian Competition and Consumer Commission was announced on Dec. 22.

It was an answer to what many who saw the ads wondered: Do the colorful silicone bands actually work?

Critics railed against the company on Twitter and those who had believed in the bracelet’s power.

The company unleashed a torrent of its own tweets, playing off the word “admit.”

In one, it said: “Power Balance Admits products have been worn during the last world series, nba finals and super bowl champions!”

Fans insist the bands have helped their game.

“Our trainers swear by it,” Phoenix Suns forward Jared Dudley wrote in a message posted on his Twitter page.

The colorful wristbands, which sell for $29.95, have become ubiquitous, donned by Los Angeles Lakers’ Lamar Odom and English celebrity soccer star David Beckham.

They have also been worn by celebrities, including actors Robert De Niro and Gerard Butler.

The company sold $8,000 of merchandise in its first year and expects more than $35 million in sales in 2010.