Police are appealing for help from the public to solve the mysterious death of a father found in the Murray River in Victoria almost six years ago.
Terrence McCallion was found fully clothed in the water by people onboard a houseboat between Bruce's Bend and Psyche Pumps in Mildura on the afternoon of May 1, 2015.
Another man was on the bank at the time and began yelling out for those on the houseboat to help.
The man, who is a person of interest to police, is believed to have left the scene in Mr McCallion's white Nissan Pulsar shortly after.
The group used a small boat to recover Mr McCallion and began performing CPR on him before emergency services arrived. He died in hospital later that night.
Detectives believe the 55-year-old was assaulted prior to his death and have spoken to the man of interest a number of times.
They have released images of Mr McCallion's car, which had a distinctive spider sticker on its back-right door, in the hope someone may have seen it either before or after the incident.
Detectives are also hopeful community members may have information about his whereabouts in the lead up to his death.
"We haven't given up on solving the case and are hopeful someone in the community is now ready to come forward with information," Detective Acting Sergeant Adam Bryme from the Mildura crime investigation unit said on Tuesday.
"Terrence's family have a right to know of the circumstances in which led him to his death so they can get the closure they deserve."
"No matter how small or insignificant the information may be, it could be all we need to piece together the case."
In a statement, Mr McCallion's family said they have been left wondering what happened to him and why.
"The death of a parent is never easy but the violent nature of dad's death and the mystery surrounding it made it especially traumatic," the family said.
"Dad welcomed everyone into his home and created an extended family that he loved as his own.
"Answers will help give us much-needed closure, so we can finally move forward from the constant pain of not knowing, to remember him for who is was and what he meant to each of us."