Pipelines vital to Iraq's oil industry are in such poor condition they could rupture at any time, choking off the supply of oil from the region and devastating the country's economy, according to the US State Department.

A previously undisclosed notification to the US Congress, obtained by the Financial Times, says the ageing underwater pipelines, which link storage facilities near Basra to offshore tanker fuelling terminals, are in urgent need of back-up or repair.