A former detective believes he has the key to finally solving the murder of Nairn banker Alistair Wilson.
Peter Bleksley, who spent 21 years with the Metropolitan Police, thinks he has unearthed a motive which could help find the killer.
Mr Bleksley has refused to reveal what that might be, but he will travel to the Highlands this week to continue his investigations into the case.
Mr Wilson was a 30-year-old business manager with Bank of Scotland. He was shot three times on November 28, 2004 on the doorstep of his home.
He lived in Nairn with his wife Veronica and two young sons.
Mr Bleksley explained: “This is a case in which the police have said, right from the early days, they haven’t been able to establish a motive for. If you find the motive, you very often find the murderer.
“I think I have discovered potentially a very credible motive for the murder. But I need to put some flesh on the bones, broaden it out and research it more thoroughly.”
He has travelled to Nairn a number of times over the years and reported on the murder for the BBC.
He added: “I have written to Veronica and asked her to speak to me. I am still waiting on a reply. I have been in contact with Police Scotland asking for an interview with someone involved in the case, I am still waiting on a reply.
“Regardless, if Veronica and the police don’t want to talk to me, it will not deter me. I will not stop.”
Mr Bleksley will be in Nairn from Wednesday until Sunday and stated: “I am going to be showing leaflets through letter boxes and into peoples’ hands.
“I will be revisiting the scene, meeting people, talking to people, spreading the word and listening to what everybody has to tell me.”
The ex-detective, who helped set up Scotland Yard’s undercover SO10 unit, will revisit the killing for a new book looking at Britain’s most baffling unsolved murders.
At the time of his murder, Mr Wilson was getting his children ready for bed.
He was rushed to Raigmore Hospital, but doctors were unable to save him.