Rugby World Cup chief Martin Snedden described New Zealanders' treatment of Australian fans as "disappointing" Thursday, after fierce trans-Tasman rivalries took on a spiteful edge. Australian fans complained of being spat on and abused when the Wallabies slumped to a shock defeat against Ireland in Auckland last weekend, identifying New Zealanders, not travelling Irish fans, as the culprits. Australia and New Zealand have always enjoyed a healthy level of sporting one-upmanship but Snedden said it would be uncharacteristic if it had crossed the line into outright hostility. "The overwhelming response here has been one of welcoming and supporting the visiting teams and their fans," the Rugby World Cup 2011 chief executive told the Sydney Morning Herald. "If some visiting Wallaby fans have not been welcomed this way, we would be very disappointed as this would definitely be out of character with the way New Zealanders have looked after our visitors over the past two weeks." An online poll conducted by the Sydney newspaper found 61 percent of 10,500 respondents felt threatened attending a game with New Zealand rugby supporters. The home fans' rancour towards Australia has been partly fuelled by New Zealand-born Quade Cooper's presence in the Wallabies' team, particularly as he has a reputation for needling the All Blacks' revered skipper Richie McCaw. The Wallabies are also seen as perhaps the main obstacle to the All Blacks' hopes of breaking a 24-year World Cup drought, explaining the unrestrained glee with which many New Zealanders greeted Australia's 15-6 loss to Ireland. All Blacks assistant coach Steve Hansen admitted he was enjoying Australia's discomfort but said the historic rivalry was tempered with respect. "I mean we've gone to war and fought shoulder to shoulder," he told reporters on Wednesday. "They're probably looked upon as the big brother and we're the little brother, we want to belt them, they want to belt us. "So if they're suffering a bit at the moment, the little brother will be smiling and chuckling away won't he? So we'll enjoy that while we can." However, TVNZ presenter Alison Mau, an Australian who moved across the Tasman in the 1990s, said she had never seen such vitriol against her homeland. "For the first time, I feel there might be a bit more to it that just good fun between mates. It worries me," she told the New Zealand Herald. "The worst sledges (insults) are generally fuelled by alcohol and are both unprintable and not worth the ink." She attributed the animosity to New Zealand's inferiority complex about Australia, which is both richer than its neighbour and has long enjoyed sporting ascendancy, including winning two Rugby World Cups to New Zealand's one. "In economics and in sport, we -- and I mean kiwis -- feel like the junior version and it doesn't sit well with us," she said. "On top of that, the Aussies are second only to the Americans for supreme self-confidence, and that can wear thin after a while." A survey published in the lead-up to the World Cup found Australia was the team New Zealanders least wanted to win the tournament if the All Blacks were eliminated. The Wallabies polled 33.8 percent on the survey of 750 people, almost doubling the next least-popular nation South Africa's figure of 18.6.