Governments have been warned that any move to regulate overbooking practices on airlines could raise ticket prices. The International Air Transport Association warned that lawmakers and regulators should not get caught up in the “groundswell of outrage” following the forced removal of 69-year-old Dr David Dao from a United Express flight so staff could take his seat. IATA director general Alexandre de Juniac said everyone, including United, agreed there was no justification for what happened to Dao and the airline’s chief executive had repeatedly apologised. "The video was so shocking that it would be easy for lawmakers and regulators to get caught up in this groundswell of outrage and take steps to limit overselling of flights,’’ de Juniac said. “However, the management of overbooking has actually worked well for decades. “It ensures that scarce capacity is efficiently utilized; we see that in today’s record load factors. Overbooking helps airlines avoid empty seats, and that helps to keep costs—and fares—low. “Governments have acknowledged that this ultimately benefits consumers. “ De Juniac said any industry level change should involve transparent fact-based dialogue between industry and regulators. “We must be careful to not risk undoing the many benefits unleashed by the competitive forces of deregulation,"  he said. The comments come as legislators in the US are threatening to introduce bills addressing issues such as overbooking and airline earlier this week faced a congressional committee looking at passenger rights. A number of US carriers, including United,  have pledged to address the issue voluntarily. The increased focus has also seen a spate of media and social media reports about passengers claiming they are being mistreated by airlines. The latest of these saw Delta Air Lines apologise to a Californian family after they were removed from a plane in Hawaii after they refused to give up a seat they had bought for a son was not travelling with them but was occupied by his two-year-old brother. The family claimed a flight attendant told them the mother faced jail and their children would be taken from them unless they gave up the seat. They disembarked from the redeye service to Los Angeles and were forced to find a hotel and book another flight the next day at a cost of $US2000. "We are sorry for the unfortunate experience our customers had with Delta, and we’ve reached out to them to refund their travel and provide additional compensation,’’ the airline said.