The 2005 Foot and Mouth disease hoax

In May 2005, in a suspected capping stunt, a letter was sent to the New Zealand Prime Minister claiming that foot and mouth disease had been released on Waiheke Island and would be released elsewhere unless money was paid and tax reforms made. A full agricultural exotic disease response was initiated. Movement controls were imposed on island livestock and animals were tested every 48 hours for symptoms of the virus. A positive return would devastate New Zealand's agricultural exports. The economic cost of the alert has been extensive regardless of the outcome. After three weeks of testing, no infected animals were detected and the response staff were stood down and was announced as a hoax.

TVNZ report