As he opened a shed door he was catapulted back by a large explosion, which killed him instantly.

Lithgow Duty Officer Inspector Chris Sammut said Mr Burrows was the victim of a targeted attack and was killed by an improvised explosive device.

On Sunday, his family and the local community held a candlelight vigil to mark the one-year anniversary since Mr Burrows’ death.

The vigil was held in Villiers Street and attended by Mr Burrows’ family, friends, the community and investigating police officers.

Mr Burrows’ family members spoke at the vigil and made a plea for people to come forward with information.

“He was a funny, well loved bloke,” his brother Gary Burrows said.

“Somebody knows something. It was a callous act. It was a bomb.”

Gary said his brother’s death had shocked the Portland community.

“There was not a person who did not know him,” he said.

Inspector Sammut addressed those in attendance at the vigil and said a segment of the bomb that killed Mr Burrows was the focus of the ongoing investigation.

“We do know at the time that device was detonated components of this device did travel up to 200 metres from this location,” he said.

“Most of the components of the device had been recovered, but the top was still missing.

“It would be described a solid plate disc, steel construction, probably 15 centimetres in diameter.

“We believe that it may have been thrown from this location into nearby bushland.”

The Blue Mountains Bomb Squad, along with forensic personnel were among the initial investigation team following the explosion at 6.30am on July 24, 2015.

Strike Force Avail was established in July, 2015 to investigate the circumstances surrounding Mr Burrow’s death.

The strike force includes Chifley Local Area Command detectives who are receiving input from the State Crime Command’s Homicide Squad.

Police have urged anyone with information to call Crime Stoppers on 1800 333 000.