Poland says Oder tests not so far showing poison as cause of fish die-off

Poison cannot be ruled out as the cause of mass die-off of fish in the Oder river but tests so far have not proven toxic substances were to blame, Polish Environment Minister Anna Moskwa said on Sunday.

Tonnes of dead fish have been found since late July in the river Oder, which runs through Germany and Poland. Both countries have said they believe a toxic substance is to blame, but have yet to identify what it is.