A criminology professor has said he believes the murder of a banker shot on his doorstep almost 13 years ago is now "eminently solvable" after receiving new information.

Father-of-two Alistair Wilson, 30, was gunned down in Nairn in the Highlands on November 28 2004, as he prepared his children for bed.

The murder of the 30-year-old remains unsolved despite an extensive police investigation.

David Wilson, Professor of Criminology at Birmingham City University, told BBC Radio Scotland he was recently sent a package containing new information about the case and now believes it can be solved.

The package, from a sender identified only as Nate, claimed there was an independent witness to the murder and named this person, the details of whom were not revealed on air but have now been passed to the police.

Previously, Professor Wilson said Mr Wilson's widow Veronica was believed to have been the sole witness.

The second piece of information in the package is the name on the envelope handed to the banker before he was shot, which was revealed as "Paul".

Professor Wilson told the John Beattie show: "I'd always previously assumed that this was a master hitman who carried out this particular crime and the case would be unsolvable.

"Because of what the package contains, if it is accurate, I now think it is eminently solvable."

He questioned, if there was an independent witness, why the police had not produced an e-fit of the killer.

The professor also said he wanted to know if the police had a forensic accountant look at Mr Wilson's banking clients.

The academic said he initially believed the eight-page package, entitled "Alistair Wilson: A Cold Case Thesis", which was sent to his university address with what he believes is a Glasgow postmark, came from a "good armchair detective".

However, the new information contained in the document made him reconsider.

On the evening Mr Wilson was shot, his wife opened the door to a stocky man, aged 35-40, wearing a dark jacket and baseball cap and holding an envelope. He asked for her husband by name.

Mr Wilson spoke to the man and then went back inside to speak to his wife before returning to the door, where he was shot.

He died later that evening in hospital.

The gun was recovered from a drain near Mr Wilson's home 10 days after his murder.