A DNA profile has been identified in the cheese wire murder of taxi driver George Murdoch.
The breakthrough was announced on Friday – on the 40th anniversary of the brutal killing in Aberdeen.
No one has ever been arrested in connection with the case.
Mr Murdoch, who was known as Dod, was attacked with a cheese wire in his taxi on the evening of 29 September 1983.
The 58-year-old had told his control room that he was heading to Culter, but he never reached his destination. He was attacked at around 8.45pm after turning on to Pitfodels Station Road on the outskirts of the city.
Police Scotland’s major investigation team continue to review and investigate the case, and have now revealed advancements in forensic analysis have enabled a DNA profile to be identified.
Detective Inspector James Callander said: “We have identified a DNA profile which may assist our ongoing enquiries.
“I would ask everyone to think back to the time George was murdered and if you have any information or concerns from around that time, please don’t dismiss it and contact us.
“We are hopeful this DNA evidence will allow us to progress this enquiry for George’s family.”
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Last year, officers issued an appeal for information to track down a man seen in Wilson’s Sports Bar on Market Street, Aberdeen, in September 2015.
He was wearing an Iron Maiden t-shirt and was described as small, stocky, in his 60 or 70s, and local to the city.
Officers believe he may be able to help with the investigation.
In a statement released through the force, Mr Murdoch’s family said: “Our family was rocked by what happened to Dod and it continues to affect us today.
“Forty years is a long time to go without all of the answers to what happened to him, but it’s never too late to see justice served and we urge anyone with any information that could assist the investigation, no matter what it is, to contact police.
“Dod was a gentle, likeable and kind-hearted man, who usually had a smile on his face. We all miss him terribly and hope for some closure.”