A US appeals court has ruled that hundreds of American navy personnel can pursue a compensation suit against the government of Japan and Tokyo Electric Power Co. for illnesses allegedly caused by exposure to radioactivity in the aftermath of the 2011 accident at the Fukushima Dai-ichi nuclear plant.

The 9th US Circuit Court of Appeals in San Francisco ruled on Thursday that the 318 sailors who have so far joined the $1 billion (£787 million) class action lawsuit do not need to file their case in Japan.

Most of the plaintiffs were aboard the USS Ronald Reagan, an aircraft carrier that was dispatched to waters off north-east Japan after the March 2011 meltdown at the Fukushima plant. Three reactors suffered catastrophic meltdowns and released large amounts of radiation into the atmosphere after their cooling units were destroyed by a magnitude-9 earthquake and a series of tsunami.

The plaintiffs claim that they were healthy and physically fit before they were exposed to the radiation plume, with some personnel reporting the air on the flight deck tasting "metallic".