Sovereign citizens have disgracefully claimed the fatal shooting of two police officers was staged, in a disturbing and false conspiracy theory.

Dezi Freeman, 56, went on the run after being suspected of gunning down the two officers in cold blood at a property in Porepunkah, 300km northeast of Melbourne, on Tuesday.

Detective Leading Senior Constable Neal Thompson, 59, and Senior Constable Vadim De Waart, 35, were shot dead while attempting to serve a search warrant.

A third officer survived after undergoing surgery and is expected to recover.

Police say Freeman, also known as Desmond Filby, is believed to be a sovereign citizen, part of a fringe anti-government movement that rejects the rule of law.