Powerful oil industry insiders have moved to quash talk of stronger prices this year, warning that turmoil in emerging markets will delay any significant recovery until at least 2017 and sending the price of US crude below $30 a barrel again. As the industry gathers in London for a big annual conference, one of the world’s biggest oil traders and a leading forecaster have both cautioned against believing the worst price rout in a generation is over. The International Energy Agency (IEA), the adviser to industrialised nations, said the global oil surplus was bigger than previously estimated and the recent rebound in prices was probably “a false dawn”. The glum tone helped send oil prices falling again on Tuesday. Brent fell 6.5 per cent to $30.78 a barrel and West Texas Intermediate declined 4.5 per cent to $28.34 in late US trading. Meanwhile, Vitol, the world’s largest independent oil trader, said the demand “bump” from cheaper petrol prices would fade and predicted crude oil stocks would pile up as consumption in China and commodity dependent economies slowed.