Police are hunting a hit-and-run driver after a 67-year-old man was found fatally injured in a Dundee street.
John Ogston was discovered lying in Mains Road, at the junction with Bayne Square, at about 23:00 on New Year's Day.
He was helped into his daughter's house in Bayne Square by four passers-by but died later in Ninewells Hospital.
Det Ch Insp Iain Wales urged the driver to "do the right thing" and come forward.
He said Mr Ogston was a father of two and retired from publisher DC Thomson seven years ago.
Det Ch Insp Wales said: "We are now satisfied that John's injuries were not the result of an assault, but were more than likely caused by a vehicle.
"At this time the vehicle has not been identified.
"His family, who are understandably devastated, are now wanting to know what happened to their dad."
CCTV showed Mr Ogston returning from the Bowbridge Bar in Main Street with a woman who was assisting him, when he had a fall.
Det Chf Insp Wales said: "She has been escorting him home and at one point she's left him for a matter of minutes in order to go and get his daughter to assist him into the house.
"It's our belief that while she has been getting the daughter out of the house, a collision has occurred.
"The indications are that he was lying on the floor and was crushed by the vehicle, rather than standing up and being struck."
Det Chf Insp said that officers wanted to trace four men who helped carry Mr Ogston into his home.
He said: "I would like to stress that there is nothing to suggest that these persons were involved in John's death, but did their best to help him, and may have seen the vehicle involved.
"One of them was wearing a distinctive top with a dark body and long white sleeves.
"Secondly, we are appealing to the driver of a taxi that drove up Mains Road from Dens Road.
"The taxi was a five-passenger size with a large passenger cabin."