A Canberra man has pleaded not guilty to the murder of Bobby Stuart Allan late last year.

Dean Phillip Welsh, 49, entered the plea when he appeared in the ACT Magistrates Court on a charge of murder on Thursday.

Welsh did not apply for bail during his brief appearance before Magistrate Glenn Theakston.

Police arrested Welsh in Griffith on Wednesday after a seven-week investigation into the death of Mr Allan in front of a Goodenia Street home in Rivett on December 17.

Police said Mr Allan may have gone to the home for help about 5.25am after he suffered critical injuries in an assault.

He died at the scene.

Forensic investigators cordoned off the street and homicide detectives removed items, including a baseball bat, from a white car parked in a corner of the nearby Noah's Ark Family and Community Centre carpark in Bangalay Crescent.

The car was taken away the following day.

Detective Acting Superintendent Mark Steel said during a press conference on Thursday morning that Welsh's arrest was a significant breakthrough in the investigation.

"Mr Allan's family has been informed of his whereabouts," he said, referring to the accused man.

"This goes a long way to achieving justice for the family."

The investigation into the murder continues and homicide detectives anticipate further arrests.

Welsh entered custody without struggle as police arrested him on a street in Griffith, Detective Acting Superintendent Steel said.

Information from the public played a significant role in the lead-up to the arrest, he said.

He said Mr Allan's family had shown courage despite a traumatic time.

Welsh was remanded in custody to reappear in court in May.

ACT Policing urged anyone who may have any information in relation to the murder of Bobby Allan to contact Police on 131 444, or Crime Stoppers on 1800 333 000 or via https://act.crimestoppers.com.au.

Quote reference number 6211559.