In 2011, Mr King outlined his ideas in a 12-page essay, Microchipping of human subjects as a productivity enhancement and as a strategic management direction of NSW Police.

The paper was submitted to a police leadership conference shortly before he was promoted from Cabramatta to Liverpool.

''What has limited our effectiveness for decades has been the restriction on how police obtain information and having to prove before courts that we have acquired our information by legitimate means,'' he wrote.

''What I propose and will endeavour to convince the reader of, is the implementation of microchip technology similar to that used in controlling the activity of domestic animals, will quantifiably enhance the success of law enforcement.''

The most controversial part of Mr King's plan was the means by which microchips would be inserted into the body. He named Danish company Empire North as having patented the ''ID Sniper Rifle'' as the ''long-distance injector'' of the microchip.