PUBS and saunas – businesses that quite often go hand in hand with a criminal underbelly, where illicit deals may be struck and dodgy pacts made under counters and behind backs.
Billy Sibbald was involved in both the licensed trade and the sauna industry. But on the surface, at least, there was nothing much to suggest he was dabbling in anything more sinister than his "legitimate" business.
By all accounts, Billy was a regular guy: the archetypal cheery pub landlord when behind the bar of Portobello's Pop Inn, which he ran with wife Julie; a devoted husband and father to his three boys; a snazzy dresser with a penchant for chunky gold jewellery and good company.
But detectives believe there was more to Billy, 48, than at first met the eye – that he was a colourful character whose dalliances into that underbelly of criminality may well have cost him his life.
It is almost exactly six years to the day since Billy's grieving family laid him to rest in an emotionally-charged service at Seafield Crematorium in Leith. Mingling with the mourners were police detectives, scanning the grieving faces of the congregation, searching for any clue that might lead them to the mystery of who killed Billy Sibbald – and why.
Yet, despite theories of gangland revenge attacks, possible motives and potential suspects, Billy's killer – or killers – remain at large.
It was early evening on October 8, 2002, and Billy was preparing for his regular Tuesday night out with Julie.
His mobile phone rang, there was a brief conversation and suddenly dinner was cancelled – Billy announced that unexpected business had come up, he had to go out.
A car pulled up outside the family home in Joppa at around 8pm, Billy grabbed his distinctive Gant coat, kissed his 35-year-old wife for what would be the last time, and headed off.
His disappearance was out of character and police were almost immediately concerned. Billy, it turned out, had just sold his Orchard House sauna in the New Town – could it be that his involvement in Edinburgh's sex industry had made him a target of some kind?
Christmas passed with no word from Billy. His family and police appealed for information concerning his disappearance, Julie urging anyone who might not want to speak directly to the police to visit her at the pub. But it was met with a wall of silence.
It was three months after he was lured from his home by that phone call that Billy's body was found.
A man walking his dog had made a horrific discovery – the badly decomposed body of a man in undergrowth beside the A1 near Musselburgh.
The body had been stripped of clothes and jewellery, as if to conceal the victim's identity for as long as possible. Eventually, DNA tests confirmed what Billy's family had been dreading – his body had been found.
Billy had been stabbed several times in what police described as a "violent and substantial" attack.
It's thought he was killed elsewhere, his body stripped, the Gant jacket probably destroyed and his gold bracelets and distinctive Du Pont lighter disposed of, before his remains were ditched in remote woodland beneath a flyover section of the road.
Later, a car stolen in Edinburgh the night Billy disappeared was discovered burned out just a few miles from his body – almost certainly used by his killers.
Naturally, the rumour mill went into overdrive. Billy, the friendly pub landlord, was quickly emerging as having a more sinister side to his character.
His wife has denied suggestions that he was a gangland figure who dabbled in heroin deals and rubbed shoulders with some of Scotland's most notorious criminals.
"It's ludicrous," she said at the time. "My kids have got to grow up listening to this stuff about their dad, but none of it has been proven.
"He was a great dad. He was just your typical laughing, giving father, who was there for them when they needed him.
"Everyone that knew him locally, his friends, will all tell you the same thing: he was good-natured and good-humoured.
"He was no saint, I am not saying that, but it's all been exaggerated."
Detectives investigated several theories suggesting Billy's murder was a gangland hit.
One theory was that he crossed paths with a violent Glasgow gangland figure, Martin Hamilton, nicknamed the Butcher of Blackhill, who had quit his home city to ply his drugs trade and run his pub and brothel protection racket in Edinburgh.
Somehow – perhaps a drugs deal gone wrong or a missed payment for his own protection – Billy ended up owing Hamilton money.
Fearful for his own safety, it's claimed that Billy approached another gangland figure – the notorious Tam 'The Licensee' McGraw – to deal with Hamilton. Money is said to have changed hands, but McGraw double crossed the publican and instead simply pocketed the cash.
Police travelled to Glenochil Prison in Perthshire to question Hamilton about Billy's murder. Hamilton was serving a life sentence at the time after being found guilty of ordering a trail of terror and torture as he tried to muscle in on the Edinburgh drugs trade.
Another theory explored by police was that Billy's vice trade links placed him in danger from a new breed of sauna bosses in the city: Eastern Europeans trying to muscle in on the scene with girls brought, sometimes against their will, to work in brothels.
It's even been claimed that Billy's death was ordered by the Russian Mafia after he fell foul of their plans.
Despite extensive investigations, police were never able to prove any gangland link to the murder.
A reward of thousands of pounds put up by the family in the aftermath of his death brought in nothing. All police received by means of help from the public was an anonymous letter containing newspaper clippings and a name.
Today, a police spokeswoman confirmed that the murder inquiry continues. "The investigation into the murder of Billy Sibbald remains unsolved and, as such, continues to be an open investigation," she added.
"As with any unsolved murder investigation, the case will be reviewed to determine whether further police action is required."
Billy's widow Julie last spoke out in 2007, when she made an impassioned plea for information to help solve the mystery of his death.
"Billy's three boys have been to hell and back over this," she said at the time.
"We need some answers so we can move on. They loved him so much, he was a wonderful dad."
Her husband, she added, was "no angel", but it was his family who were still paying a terrible price. "We are the ones who are suffering, we need to know what happened," she said.
"Billy knew so many people, someone must have some answers. Then we can finally let him rest in peace."