Kellerberrin police standoff ends with fatal self-inflicted gun shot wound

The man in question was believed to be responsible for the fatal shooting of a man in his 40s at Moylan Grain Silos at about 8.40am, which then sparked a massive manhunt and parts of the Wheatbelt community were put into lock down.

Police were originally on the lookout for a man in a grey Holden Commodore but then confirmed the person they were looking for was then "on foot".

Tactical response police tried for a couple of hours to negotiate with the man after he was located on a farm, about 20 kilometres north of Kellerberrin.

While negotiations were underway, police had medical staff and a rescue helicopter on standby in what has been described as a "rapidly evolving" incident.

Police would not confirm what firearm was involved in either incidents, only to say the 25yo had several firearms licensed in his name.

They confirmed the two men were known to each other, being work colleagues for several years.

The man was not known to police.

Police thanked members of the public for their assistance, saying it was "a tragic outcome for everyone involved".

Police have yet to speculate on a motive for of Thursday's shooting and said homicide squad members would be leading the investigation.

There have also been reports that a member of the public was inside a vehicle when he was allegedly shot at by the 25yo, however there were no injuries.