Breakthrough in shooting that killed two cops and a neighbour as man is arrested in the United States

A man has been arrested by FBI agents in the US in relation to the shooting on a remote property that tragically claimed the lives of two Queensland police officers and a Good Samaritan neighbour almost a year ago.

Constable Matthew Arnold, 26, and Constable Rachel McCrow, 29, were shot dead by Nathan, Gareth and Stacey Train when they attended their Wieambilla property in the state's Western Downs in December 2022.

Neighbour Alan Dare was also killed in the siege before Nathan, Gareth and Stacey were all shot dead by police hours later.

A police investigation later found that two slain constables were fatally ambushed by the Trains who had links to the sovereign citizen movement and subscribed to a Christian fundamentalist belief system known as premillennialism.

The FBI announced on Wednesday that agents arrested a US man, 58 near Heber Overgaard, north-east of Phoenix in Arizona following an extensive investigation in partnership with Queensland Police.

Police made the arrest on December 1 in what they say was 'connection to the religiously motivated terrorist attack'.

Investigations are ongoing.

The breakthrough comes after Queensland Police investigators from the ethical standards and security and counter terrorism commands recently travelled to the US.

Queensland Police have advised that the families of the slain officers and Mr Dare have been informed of the latest developments, along with the coroner.

Two officers injured in the shooting ambush- Constable Keely Brough and Randall Kirk have also been informed.

Police are set to provide more details in a joint press conference with the FBI later on Wednesday.

Next Tuesday will mark the one year anniversary of the tragedy which shocked Queensland.