Detectives said police were particularly keen to hear from people who had contact with Mr Sofer-Schreiber or witnessed suspicious activity in the Lyneham area around the Christmas period.

Mr Sofer-Schreiber, a legally blind orphan, was found dead with multiple stab wounds in his Hall Street unit on December 28.

Friends found the avid punk fan's body when they went to his home after he had not been seen since Boxing Day.

Authorities have previously said there were no signs of a struggle or forced entry, and burglary or robbery did not appear to be a motive.

Criminal investigations detectives are continuing to investigate the homicide, and have previously stated they have identified several “persons of interest” and the case was progressing.

Former housemate, Don McFadden, on Thursday urged anyone with information on his friend’s death to speak up.

“If there’s anybody out there who has any information at all, please come forward,” Mr McFadden said.

“Every little bit helps.

“Everyone’s desperate to know what’s happened to him so any help would be greatly appreciated.”

Mr McFadden remembered his friend as a good guy, with a huge heart, who loved music and "had plenty of time for everybody".

“It’s just horrible this happened to him really.

“[We have] no idea why [he was murdered], that’s probably the most frustrating thing.

“He was a gentle guy, he wouldn’t hurt a fly, I can’t think of any reason why anyone would want to do this to him.”

Detective Sergeant Donna Parsons said police were following up a number of avenues of inquiry but were keen to receive information about contact with Mr Sofer-Schreiber around Christmas.

“Every little piece of information … no matter whether they think if it’s big or small … is important and we are thoroughly investigating everything that comes to us.

“Obviously there’s people out there that know something so we’d encourage them to come and report.

“The period the incident happened was over Christmas, people may have been away, so if anyone’s been away and just recently found out what’s happened, if they can contact us that would be really important.”

The call comes a day after police urged two witnesses to come forward who may have seen Miodrag Gajic’s killer at the cannabis dealer’s Phillip apartment complex on New Year’s Day.

Detectives said two women could hold “crucial” information to their homicide investigation, now entering its third week.

Mr Gajic, 71, was found dead with severe head injuries in his apartment on Mansfield Place on January 1.

Screams were heard as friends discovered Mr Gajic’s body, hours after he is thought to have been killed.

It was revealed on the weekend that a suspect linked to the murder was in custody on unrelated charges.

Police were tipped off to the existence of the two women by other witnesses they have talked to in the weeks following Mr Gajic’s death.

Detective Sergeant Anthony Brown said the women were not suspects and urged the pair to come forward.

“The two women were walking into or around Mansfield Place on the morning of the incident,” he said.

“We believe they may have seen other witnesses or possibly our offender coming into or leaving Mansfield Place and our victim’s residence.”

The only description available of the women is that one is middle-aged, and the other mature-aged.

Police and emergency services scoured bushland in Red Hill as their investigation into the killing continued on Thursday.