The detective leading the hunt for the murderer of 63-year-old John Kennedy has said the time frame for the killing has narrowed significantly after a witness came forward.

Senior Investigating Officer Gary Ogilvie confirmed that an individual had approached inquiry officers to confirm they had been at the address in Mossgiel Crescent at 9pm on Sunday.

Mr Kennedy, who was formally identified following a post mortem on Wednesday, died as a result of a fatal attack in his home at about 10.15pm on Sunday.

DI Ogilvie said: ‘‘It was a brave step for this person to come forward and assist us with our investigations and we are extremely grateful that they did so. Their information has been of value to us and we are satisfied they had nothing to do with Mr Kennedy’s death.

‘‘We know for a fact that many people visited that address during the day and through the evening, day in day out. There were visitors to that address on Sunday and we want to speak with each and every one of them.

‘‘The response so far to our appeals for people to get in touch has been excellent, but there are others who are not making themselves known. They need to get in touch as a matter of priority.

‘‘They might be nervous about the repercussions of coming forward because, as it has been revealed, John used to sell cigarettes and tobacco to people from his home address. As I have said before, I have no interest whether or not they were there to buy these things from Mr Kennedy. I am investigating a murder and they may have information that could help to trace the person responsible. They need to come forward.’’

The detective earlier described the murder as "vicious and frenzied" and a "sustained attack".

He added: "The person responsible has fled from the scene and he would have been heavily blood stained."

It has also been suggested that Mr Kennedy’s house was subject to a sneak-in theft or break-in in recent weeks. While no complaint was ever made to the police, that is something that the inquiry team is keen to learn more about and anyone with information should get in touch.

Around fifty officers are currently involved in the enquiry, including detective officers, uniformed officers and scenes of crime officers, with support from the CCTV team, researchers and officers and staff working on the Home Office Large Major Enquiry System (HOLMES).

Around 100 houses in the area have been visited by police officers seeking information, generating almost 260 questionnaires. Over 100 statements have also been processed by the enquiry team.

A significant police presence remains in the Linlathen area of Dundee where Mr Kennedy lived.

Scenes of crime officers continue with their examination of the Mosssgiel Crescent address and the surrounding area. Well over 200 productions have been recovered, and those items of greatest interest have been prioritised for detailed forensic examination.

Residents have also encouraged to search their own gardens, outhouses, garages and bins and report anything amiss or out of place to the police.

Anyone who has information useful to enquiries should call Tayside Police on 0300 111 2222 or speak to any officer. Alternatively they can call the charity Crimestoppers anonymously on 0800 555 111.

There is also a line, which is Dundee 01382 591941, which directs callers straight to the Enquiry Team during normal office hours and to the Force Communications Centre out with office hours.