Seal deaths raise fears about nasty strain of bird flu

Signs of a highly contagious and deadly strain of bird flu have been observed on a remote Australian sub-Antarctic island for the first time.

Scientists say the presence of H5 avian influenza on Heard Island, about 4000km southwest of Perth, hasn't been confirmed and they won't know for sure until more testing is done.

Australia is the only continent in the world free of the H5 strain of bird flu, which has spread across most parts of the globe, including sections of Antarctica.

Scientists on a research voyage to the world heritage listed island have noticed unusual levels of mortality in elephant seals in recent days.

"Australian scientists have observed signs consistent with H5 avian influenza in wildlife," the federal environment and agriculture departments said in a joint statement