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Police have backed down from prosecuting a man who allegedly threatened to contaminate a river with rock-snot, or didymo.
The man allegedly threatened to release didymo into the Waiau River near Wairoa in protest against DOC's use of the poison brodifacoum to control rats and possums.
Detective Sergeant Mick Lander said police sought a Crown legal opinion of what charges could be laid against the man.
He said lawyers advised police that a prosecution would not be successful, due to technical scientific issues relating to didymo.
Police were considering laying charges of threatening to cause serious damage and blackmail.
"In short, didymo did not reach the legal threshold required to constitute serious damage. We had to work within the legislation that is in place and in this instance, legal definitions under the Crimes Act prevented us from taking the case any further," Mr Lander said.
Didymo is classed as an unwanted organism under the Biosecurity Act 1993 and it is an offence to knowingly spread it. Penalties range from up to five years' jail and/or a fine of up to $100,000.
