A suspected third case of the devastating banana disease, panama, has been discovered in far north Queensland where eighty per cent of the country’s bananas are grown.

Samples from the Tully Valley taken last week have tested positive for Panama tropical race 4, a disease which doesn’t affect the fruit itself but rapidly kills cavendish banana plants.

The Department of Agriculture and Fisheries said further testing will be conducted to determine how wide spread the disease is, but has warned this could take up to six weeks.