A police officer who was also a "keen pig hunter" had an unacceptable conflict of interest during a poaching sting operation in Otago, an investigation has found.
The Independent Police Conduct Authority (IPCA) has released its report on the actions of two officers, who were also recreational pig hunters, during Operation Poacher in 2013 and 2014.
Its findings have kicked off a national policy review into police blanket trespass notices.
Operation Poacher began in 2010 with police issuing trespass notices as an answer to the spate of theft, drug, vandalism and poaching offences in forests throughout the Southern police district between 2007 and 2009.
The IPCA received multiple complaints from local pig hunters in late 2013 and early 2014 relating to blanket trespass notices banning them from 147 forestry blocks in Otago and Southland.
Its report said pig hunting could be a highly competitive pastime that could lead to "defensive behaviour and ill-feeling" between members of the hunting community.
Three of the complaints came from two pig hunters who were searched by two police staff, referred to as officers A and B, in a remote area of a commercial Berwick forest on August 2, 2013.
The IPCA found the blanket trespass notices were unjustified but there was no evidence of corrupt behaviour.
One of the officers was found to be in a strong position of conflict because he hunted on the forestry land while also policing unlawful activities.
The IPCA recommended all Operation Poacher trespass notices issued be reviewed and police policy amended.