The final moments of two young police constables killed in an ambush at a remote Queensland property have been described as execution "in cold blood".
Police shot dead three people following a siege on Queensland's Darling Downs on Monday night, after the two officers and a neighbour were gunned down.
Constables Matthew Arnold, 26, and Rachel McCrow, 29, were responding to a call for a missing person when confronted by a "hail of gunshots" after jumping a fence, Queensland Police Union president Ian Leavers told ABC Radio National on Tuesday.