The last time Quentin Griffiths was seen alive he was disappearing into a lift that whizzed him to his 17th-floor penthouse. Wearing a polo shirt and shorts, he had parked his £200,000 McLaren supercar a few minutes earlier in the garage below the building in southern Thailand.

As he walked up the steps to the entrance, a porter opened the door and Griffiths, the co-founder of online fashion giant Asos and once one of Britain’s most admired businessmen, registered the courtesy with a glancing smile.

Security footage captured him entering the lobby, gaudily furnished in gold and marble. He padded into the lift clutching a red briefcase at 12.38pm and the doors closed behind him. This much is beyond doubt. As far as anyone can tell from CCTV footage, he seemed relaxed. That’s what the porter thought too.

Nothing about his demeanour, he recalls, suggested anything was out of the ordinary or gave the slightest hint of what was about to happen. For what we also know for sure is that the extraordinary life of 58-year-old Quentin John Griffiths ended violently some eight hours later on February 9, when he fell 225ft to his death from his balcony.

Friends said he called it ‘my eyrie’ and loved to sit on his Lloyd Loom-style wicker chair drinking wine, listening to music and savouring the panoramic view of the crescent-shaped bay below and the islands beyond it.

To his family and loved ones, his death was as unexpected as it was shocking.

Police in Pattaya, the garish resort on Thailand’s east coast, are satisfied Griffiths took his own life and the evidence appears to support that conclusion.

The door of his apartment in Elysium Residences was double-locked on the inside, there was no sign of a struggle and CCTV showed him and no one else entering. An open-and-shut case then, surely?

Yet much about the entrepreneur’s final weeks – indeed, his final minutes, as we have discovered – remain puzzling.

In a startling new development, the Daily Mail has located a witness who heard Griffiths angrily arguing on his mobile phone just before he toppled over the balcony’s waist-high glass balustrade. The identity of the person on the end of the line is a mystery.

The witness, a woman called Kluay, lives on a third-floor apartment overlooking the spot where he fell. When it happened, she was just 50 yards away, working in the sushi restaurant she owns in the upmarket district of Pratumnak Hill, the ‘Beverly Hills of Pattaya’.

‘I will never forget that evening. The argument was explosive and went on for minutes,’ she says. ‘He was extremely agitated and was shouting. It was around 8pm. I was just closing and clearing the tables outside. I couldn’t make out what was being said exactly but he was using the F-word a lot.

‘There was silence afterwards for about five minutes and the next thing that happened was that I heard him scream as he fell.’

Her voice trails away for a few seconds and she lowers her gaze. Composing herself, Kluay goes on: ‘My friend who works at Elysium [Residence] rang me to say that someone famous had died but I knew already of course. What I heard was this poor man’s last phone call. It is very upsetting. What I didn’t know until his picture was released was that he was the man who drove past here every day in his sports car blaring Western pop music. He always drove very slowly and he always looked sad to me.’

Undeniably, Griffiths’ troubles were crowding in on him. He was facing 18 months in jail for fraud for attempting to remove his 43-year-old ex-wife, Thai businesswoman Ploy Kringsinthanakun, as a director of the company they ran, a prospect he apparently viewed with growing dread. Meanwhile a mysterious Chinese businessman was chasing him for money.

None of his problems were insurmountable, though.

Or not nearly so bad, says an expat friend, that he should have felt compelled to end it all.

‘It doesn’t make any sense,’ he explains. ‘He had so much to live for and while he had his troubles and was stressed and drinking heavily, he often said happiness was just around the corner.’

Since his death Griffiths has been cast as a playboy whose isolated, dissolute lifestyle contributed to his demise. Yet far from living alone in his penthouse, the Daily Mail has learned that he was a doting father who spent as much time as possible with his two children, a boy aged 12 and a girl of 11, and their nanny in a rented terracotta-roofed house on the edge of a golf course at the Phoenix Country Club, a 25-minute drive south of Pattaya.

What’s more, the house stands 200 yards from an eight-bedroom villa that Griffiths was building as a larger family home. ‘People don’t know this about him,’ says a close friend. ‘He was a good father and kind to his children – which only makes his death more tragic.’

The tragedy comes against the backdrop of a rancorous custody battle over his two children with Ploy. Griffiths was granted custody by mutual agreement after they divorced five years ago.

But since his death Ploy has made clear her intention to raise the children in Bangkok even though she has seen them only once since the split. Her former husband’s family, who could also get custody, live 6,000 miles away in Dorset with Joel, Griffiths’s 29-year-old son from his first marriage back in England.

None of the case’s twists, contradictions and puzzling elements seem to concern the man in charge of policing Pattaya, Thailand’s notorious vice capital.

Superintendent Colonel Anek Sathongyu says his investigators concluded at the scene that there was no foul play. He shows us photographs they took of the inside of apartment SS03 – which appears well-appointed if impersonal – on the night Griffiths died. In one image a near-empty red wine bottle stands on a table next to a white corner sofa. In another more poignant snap, the sliding balcony door is fully open and his wicker chair is pushed up to the balustrade at an angle.

‘See, no signs of any fighting,’ says Superintendent Sathongyu. ‘It was only Quentin there. He was drinking all of the time because of the pressure he was under. And it seems he could not face prison.’

He says he knows nothing of the mystery final call and, in any case, says it has no bearing on the investigation, which is now closed. But Griffiths’ phone records would probably reveal the caller’s identity. ‘No, it’s not something that concerns us,’ he says with a sharp wave of his hand. ‘Our work is done. If he was pushed it would be a different story.’ He does clear up one mystery, though.

At the time of the businessman’s death, an unsealed yellow envelope lay on the front passenger seat of his McLaren, prompting speculation that it was a suicide note and that police had not managed to gain access to the car. ‘It turns out this was a letter relating to his appeal,’ he says.

Intrigue continues to beset the case, however, despite the policeman’s detachment.

There is the not exactly minor matter of the businessman’s fortune, though exactly what is left of it following a series of failed ventures, not to mention years of high living, is unknown.

No sooner had Griffiths’ family and friends said their goodbyes at his funeral in Dorset, than nearly £3million in Bitcoin disappeared from his crypto wallet.

It was transferred from his online account in three separate transactions in the days following his death.

Thai police are now investigating the apparent theft after it was reported by his eldest son Joel.

But perhaps the biggest mystery of all is why someone of previously assured judgment – the once clean-cut golden boy of the dotcom bubble – should end up embroiled in such a tangled mess of personal and business disputes in the first place.

Given that he walked away from shopping giant Asos with millions, some of the sums featured in these wrangles seem comparatively trifling. And that it should all be played out in the seedy resort of Pattaya, whose ‘sin city’ reputation eclipses that of Bangkok, might also surprise those who knew him well back in London.

In 2000, with two partners, Griffiths created As Seen On Screen (later shortened to Asos), a fashion website that offered affordable versions of outfits worn by TV and film celebrities.

It was a surefire hit and rapidly became a £2billion global company. The Princess of Wales, Samantha Cameron and Michelle Obama have all worn Asos’s own-label designs. Griffiths retained a 12 per cent stake in the company but sold much of his holding in 2005 to pursue new business start-ups.

Try as he might, he never matched his early success.

Adili, an online ethical fashion retailer, lost millions before being sold for £1. BeCheeky, an online lingerie store, and Everything But The Music, an online fashion retailer, also failed.

Griffiths moved to Thailand in 2010 to reduce his tax bill, but even this did not work out.

In all, he had 19 directorships in various ventures over the years, including the pet accessories website Astarpets.com, which launched in 2014 and closed in 2016. In 2015 he put money behind Farm Drop, Britain’s first ‘click and collect’ farmers’ market that delivered fresh local produce to customers’ doors. It collapsed in 2021.

In 2013, Griffiths had sold much of his remaining Asos stake, along with other shares, for an estimated £10million. Around this time he accused his accountants of costing him £4million by failing to inform him correctly on rules governing capital gains tax.

How much he was worth when he died is not known. After his death, Ploy felt compelled to come forward and state publicly that she didn’t kill him. ‘I had absolutely nothing to do with his death. How could I kill him? How would I know anything about it?’ She added: ‘I fought with him so much in the past but I moved on and just wanted to be treated fairly.’

Last October, Griffiths was sentenced to 18 months’ jail after being convicted of falsifying documents to fraudulently remove Ploy as director of a firm used to hold property for a family home.

He appealed and was due to have a meeting with her lawyers the week after he died to try to strike a deal which might have kept him out of prison. According to a friend he was preoccupied with the sum he was being asked to pay Ploy, which amounted to about £500,000, to settle the case.

The friend also recalled that the last time they met in a Pattaya cafe, five days before his death, the businessman seemed to be in a daze. He kept talking distractedly about his ex-wife and then, bizarrely, began stirring his coffee with his finger. ‘He looked like he was drunk... his head was heavy,’ he said. ‘He seemed out of it.’

It also emerged he had sold their villa without Ploy’s permission to a Chinese businessman who was furious when the sale was ruled unlawful and was demanding the return of £1million.

Friends admit it seems odd that a man of such apparent means couldn’t simply dip into his vast funds to make these problems disappear. ‘Perhaps he wasn’t as rich as we assumed,’ speculated one acquaintance.

Yet he was building another spectacular £6million villa at the golf club, which stands just off a winding road canopied by flame trees. A man called Mr Tun, who oversees development projects on the course, had given us directions saying: ‘Shortly after he died his son Joel called a halt on the building work, citing a court order. The house is now fenced off with corrugated iron.’

It was when we arrived that this troubling story took a bizarre twist. Pulling up at the house we noticed a black Mercedes parked outside and three women peering at it through a gap in the 8ft fence. One of them, wearing a lilac tunic, looked panicked when she saw us.

She appeared vaguely familiar. And then the penny dropped. It was Ploy herself, accompanied by her sister and aunt.

Was she conducting an inventory of her ex-husband’s assets? Ploy appeared to read our minds and emitted an embarrassed parrot-shriek laugh. ‘I’m just here having a look,’ she said. ‘This beautiful house is nothing to do with me.’

She went on to give a rushed account of how she had spent three days meditating at a temple because of the stress of another custody hearing last week.

‘I was allowed to hug my children in a room off the court but they kept looking down. It was heartbreaking,’ she said.

‘There were police and lawyers and others present. They wouldn’t let me be alone with them. But they should be with their mother so I will go on fighting for them. I have no idea where they are now.’ With that she disappeared into the Mercedes.

The house Griffiths rented has been empty since his death. Neighbours recall seeing the children with Griffiths, a nanny and another woman. A girlfriend perhaps? A close friend later enlightens us: ‘The other woman is Ploy’s aunt.’ The woman, then, whom we met earlier.

‘She has looked after the children with the nanny since the divorce,’ adds the friend. ‘Quentin lived there too. The aunt simply worked for him, nothing more.

‘It might seem an odd arrangement but it works. Or it did until he died. The children never saw their mother. It was decided when they split that they would be better off with Quentin because he was rich and could give them a good education.

‘I don’t know anything about the apartment where he died. The children never went there.’

Yet another oddity – and doubtless not the last before this tragic saga runs its course.