A man has been jailed for life for murdering a restaurant owner with a filleting knife almost 40 years ago.

Riasat Khan stabbed 41-year-old Kazi Ahmad seven times on the neck and chest at a flat in Aberdeen on October 13 1978.

He then fled the country for Pakistan, returning to the UK in the mid 1980s.

Khan, now 63, was arrested on a warrant as he tried to board a flight at Birmingham airport in May last year.

Lord Beckett ordered him to serve at least 16 years as he sentenced him at the High Court in Glasgow.

The judge said: "Justice has been delayed but justice has not been denied.

"The excellent work done by police officers, forensic scientists and pathologists in 1978 stood the test of time leading to your conviction for murder in 2017.

"Had you been arrested in 1978 you would no doubt have been convicted of murder with the sentence of life imprisonment and may well have been released by now.

Barrhead News:
Riasat Khan, who has been jailed for life (Credit: Police Scotland/PA Wire)

"Instead your actions have allowed you to spend the best years of your adult life in freedom."

Mr Khan, from Cardiff, was convicted following a trial at the High Court in Edinburgh where he lodged a special defence of self defence.

Khan was 24 when he murdered Mr Ahmad at 54 Rosemount Viaduct.

Lord Beckett said: "You inflicted wounds he could not have survived, however rather than seeking medical assistance for him your own evidence was that you tied him up and left the scene. I infer that you locked the door to his room as you departed.

"You took his money, gambled away £900 and fled abroad.

"As a result of your vicious assault Mr Ahmad lost his life at the age of 41 and his family whom he was supporting lost him forever. You on the other hand remained at liberty for more than 37 years before you were arrested."

Advocate Depute Murdoch Mactaggart told the court that a warrant for Khan's arrest was granted on October 16 1978, and continual efforts to trace him were made over the decades with no success.

Other police forces and Interpol were involved but Khan was not arrested until 2016.

Gary Allan QC, defending Khan, said his client was in the UK from the mid 1980s and was registered with various public authorities, and has been living openly at an address in Wales for the last five years.

Mr Allan said Khan felt remorse for his actions.

He said: "He is very sorry that at his hands the deceased died and he is very sorry for the distress which he acknowledges must have been suffered by the family of the deceased. He wishes matters could have been very different."

Mr Allan added: "He understands he will have this life sentence and he understands that in view of his age and health there is a significant risk he will die in prison."

Lord Beckett asked the Crown and the police to consider whether any lessons can be learned from the circumstances of the case and the long time it took to execute the warrant.

Mr Mactaggart said: "The Crown is very concerned about what happened in this case and that concern will be taken to the highest levels."

Detective Superintendent Jim Smith said: "Lines of enquiry since the murder in 1978 by legacy Grampian Police were limited and reliant upon cross force assistance and checking. Indications were that Khan had left the UK.

"In 2014 Police Scotland completed a review of outstanding homicide warrants. Intelligence was refreshed but no positive line of enquiry identified at that time.

"The relevant wanted markers were confirmed as in place should he enter or leave the UK. Khan was subsequently detained at Birmingham Airport on Saturday May 7, 2016.

"Evidence captured at the time of the murder clearly stood the test of time and led to his conviction of the murder of Mr Ahmad.

"As with all detected murders and other significant deaths the Homicide Governance and Review team will undertake a full debrief of this case, identifying best practice and reviewing internal process.

"We will share this organisational learning both internally and with our external partners to ensure continual improvement in practices in all investigative areas.

"The passage of time is never a barrier to ensuring that those who commit crime are brought to justice. Khan must now face the consequences of his actions."