A gang who plotted the murder of a businessman at an Edinburgh casino have been jailed for a total of 43 years.

It remains unclear why 63-year-old Tony Demarco was gunned down outside the Maybury Casino in June 2008 and a fifth man involved in the plot has still not been identified.

However, at the High Court in Edinburgh on Tuesday, property wheeler-dealer Imran Sakur, 35, was sent to prison for 11 years for hatching the plot.

Gunman Jamie Robertson, 25, and Craig Kelbie, 35, who also calls himself Craig Wallace, were both jailed for 11 years. An earlier trial heard that Wallace was Sakur's "fixer".

Getaway driver Francis McGlone, 39, was given a ten year sentence because he had spent longer on remand and a jury's verdict cut down the length of time he had been involved in the plan.

All four had been found guilty of conspiracy to murder and attempted murder "whilst acting along with another."

The trial heard how scheming Sakur laughed and joked with his intended victim just minutes before the shooting plan was put into effect. A jury saw CCTV footage of them on the steps of the casino.

Sakur also pretended to chase the black-clad gunman who sprinted away after blasting Mr Demarco in the back of the head at close range as he walked towards his silver Mercedes. A trial heard he was lucky to be alive and a bullet which bounced off his skull is still lodged in his cheek.

The court also heard how, in the days leading up to the shooting, Sakur tried to distance himself from the plot by relaying his messages through accomplice Craig Kelbie's phone.

Eye-witnesses in the Maybury area gave widely differing descriptions of the gunman and picked out the wrong man at identity parades, however, detectives who set up "Operation Muster" were left with two vital pieces of evidence.

A trawl through hours of security camera film showed McGlone's car driving around the casino in a suspicious way and even revealed the number-plate. A painstaking police search also found a spent cartridge lying in the road.

The motive was said to be debts owed to Mr Demarco. Sakur told police: "That is not me. I don't owe him a penny. Ask him yourself." And during the trial he claimed it was another man, Shahid Aslam, who owed Mr Demarco hundreds of thousands of pounds and wanted him dead.

Mr Demarco also repeatedly denied that Sakur owed him money. Other witnesses spoke of Sakur's money worries and named Mr Demarco as one of his creditors.

On Tuesday, Sakur's defence QC Brian McConnachie said: "Despite the fact that we all sat for many days listening to evidence in this case from both sides it is probably still as much of a mystery now as when we started."

Re-living the painful ordeal in court, father-of-two Mr Demarco, said: "I don't know who shot me. As I went to open my car door I heard a bang and felt a thud behind my ear, my right ear."

Mr Demarco said the bullet was still there. Medics told him that because it was so close to the carotid artery and important nerves it was too dangerous to try to remove it.

No weapon was ever recovered but police firearms expert Ronald Withers told the trial it was probably a converted starting pistol which would not have the power of a "real" firearm.

Labourer McGlone and bricklayer Robertson, both from Paisley, and property developer Sakur and unemployed panel beater Kelbie, both from Dundee, had all denied involvement in the attempt.

Sentencing them, judge Lord Kinclaven said: "Conspiracy to assault and murder is an extremely serious matter particularly where it involves the discharge of a loaded weapon and the attempted murder of Mr Demarco in a public street."

The judge made an order extending the licence conditions of all the plotters for an extra four years, warning that they would return to prison if they offended after their release.