Police are conducting a large search of bushland and a river in Queanbeyan for items related to the murder of Eden Waugh in Watson last year.
Mr Waugh, 37, was shot in the chest with a sawn-off shotgun in front of his girlfriend in his flat in Canberra's north in November.
At the time police said they were looking for two men seen fleeing the area on foot, but no-one has been officially charged with Mr Waugh's murder.
Officers also said they were investigating the link between Mr Waugh's death and a home invasion in September, in which Mr Waugh was injured.
On Saturday afternoon police began conducting a search near White Rocks in the Queanbeyan suburb of Karabar for items related to the murder.
A team of 40 people, including police divers, forensic officers and the ACT SES were involved in the search, which was expected to last a few days.
Detective Sergeant Dave Turner would not specify what police were looking for but said it would be a "significant step forward in the investigation if it's located".
He said the information that led police to search the area was "credible" and had only been obtained in the past few days.
Police have yet to locate the murder weapon.
Detective Sergeant Turner said a reward of $1,000 may be applicable for information provided to Crime Stoppers.
On Friday night Taniela Manu Pikula, 29, from Karabar was arrested by homicide detectives and charged with being an accessory to murder after the fact.
He faced court on Saturday morning where he did not apply for bail and was remanded in custody.
It is alleged Pikula assisted two men, Tavake Lee Pikula and Jason Pikula Carroll, being investigated for Mr Waugh's murder.
The two men have not been charged over the murder, but police said they expected to make further arrests during the ongoing investigation.
