Japan's worst case of industrial pollution was first discovered in 1956 after residents in Minamata, a town on the Japanese island of Kyushu, noticed that cats in the area had started to behave strangely, dancing around, screeching and scratching.

Soon people in Minamata began to show similar symptoms, including splitting headaches, tunnel vision and deformities.

Researchers later discovered that water in Minamata Bay had been polluted with mercury from waste discharged by a local chemical factory.

More than 2,000 people died from eating contaminated seafood from the area, with thousands more suffered life-long damage.

It would take years before the Chisso Corporation admitted their role in the poisoning of the environment.

Fujie Sakamoto's family was directly affected. She spoke to Witness about their fight for justice.

Witness is a World Service programme of the stories of our times told by the people who were there.