IT'S the $60 bracelet they tell you has the potential to make ordinary men into super human. So just imagine what it does for superstars such as Wests Tigers pivot Benji Marshall. The NRL has confirmed it will investigate the use of Power Balance wrist bands after Marshall (left) last week exposed one of world sport's best-kept secrets. As he lifted his arm in triumph, Marshall revealed he was wearing the Power Band during his man-of-the-match performance against the Sydney Roosters at the SFS. It is claimed the wonder band can increase an athlete's core strength and power by as much as 500 per cent. And as The Sunday Telegraph began investigating the mystery band on Marshall's wrist, we discovered he is not the only athlete using it. Parramatta's Timana Tahu and Eric Grothe, St George Illawarra's Matt Cooper and Bulldogs half Brett Kimmorley were also said to be fans of the bracelet. So are AFL superstars Nick Riewoldt and Brendan Fevola, soccer's Cristiano Ronaldo, Group I jockey Damien Oliver, Wallaby James O'Connor, NBA legend Shaquille O'Neal and world surfing champion Mick Fanning. And it's almost certain the numbers are higher, with the common practice of NRL players taping their wrists likely to be concealing just how many players are using the so-called wonder band. According to the advertising brochure, "Power Balance holograms are imbedded with frequencies that react positively with your body's natural energy field to improve balance, strength and flexibility". Highly sceptical, we put a band to the test in our office and were stunned at the results. Ordinary office workers displayed immediate improvements to their resistance and core strength. But there's a serious side to the craze sweeping through the NRL ranks, with claims the lightweight bands could be football's version of swimming's super suits. One leading player agent contacted The Sunday Telegraph to suggest "they should be banned because it was a form of cheating". "It's a distinct case of one player having an outside advantage over another," the agent said. NRL chief operating officer Graham Annesley admitted he was unware of players using the band, but told The Sunday Telegraph that their impact would be investigated. "We've also got rules in the NRL operations manual that says no items of non-standard equipment can be used in the game without prior approval by the NRL," Annesley said. "It's the first I've heard of it, so we'll obviously need to look at it and determine whether we allow them or not. We'd also take medical advice on it." The bands are made of rubber and are unlikely to be considered harmful to other players. However, Annesley added: "Referees and touch judges have the responsibility before a game of checking every player to make sure they're not wearing anything that would be considered dangerous. "It is something that we will look into."