Posted by 
Homicide squad detectives are desperately trying to trace a man's final moments before he was found with fatal injuries in a south-east Melbourne street last week.
Michael Bushby was found unconscious with significant head injuries by a passerby on Fifth Avenue in Dandenong just before 7am on Friday.
He was taken to the Alfred Hospital, where he died on Saturday.
LIVE UPDATES: Tropical Cyclone Alfred nears Queensland coast
The 52-year-old was last seen on CCTV released today by police in a bid to appeal to witnesses to come forward.
In the first CCTV clip, he can be seen leaving the motel at 6.57pm on Thursday to go for a walk – which was usual for him – and returning about 7.43pm.
Bushby walked with a noticeable limp and suffered from leg cramping, and often went for walks to alleviate the pain.
Early the next day, about 2.03am, he left the motel for another walk, and he is last shown on CCTV at 2.11am.
Bushby, from Alexandra near Lake Eildon, had been staying at the motel with his partner, a 50-year-old woman.
She reported him missing when he did not return.
Police have established that Bushby died from head injuries.
"At this stage we do believe he was assaulted and sustained significant head injuries," police said.
"We are open minded to there may have been other things that have occurred."
Police have not been able to find any footage of the victim's final movements and are urging anyone in the area at the time with dashcam and CCTV to come forward.
Anyone who witnessed anything, has CCTV, dashcam footage or any other information that could help police should contact Crime Stoppers on 1800 333 000 or submit a confidential online report.
