Hog futures prices have plunged to a seven-year low – far below the level seen earlier this year at the peak of the swine flu scare – pushing the US pork industry towards a “wave of bankruptcies”, according to industry experts.

The warning underlines the extent of the crisis within the $12bn US hog industry, the world’s biggest exporter of pork, and the mounting losses for those investors who bet that prices would recover swiftly from the flu hit.