For those gathered in the small side room of Christie’s auction house in London on a quiet afternoon last week, it was a poignant spectacle.

Before them lay a gathering of personal effects belonging to the late Sir David Tang, who died last August of cancer at the age of just 63. His passing marked the end of a life that had been as richly colourful as it was extraordinary, summed up in part by the lots now up for sale.

Among them was an Elizabeth II parcel-gilt silver pillbox, a personal gift from Prince Charles, and a striking photograph of the model Kate Moss, a close friend.

Works by Tracey Emin were mixed with exquisite silverware and furniture, the legacy of a bon viveur known not just for his vast spending and lavish parties but also his munificent generosity and eclectic taste.

Sir David Tang led a life of barely believable opulence, a crucible melding the worlds of fashion, royalty, business and art. He is pictured with model and actress Sienna Miller in 2011

A growing number of people have told The Mail on Sunday they believe Tang (above, with supermodel Naomi Campbell in 2012) died almost penniless

Tang, after all, had led a life of barely believable opulence, a crucible melding the worlds of fashion, royalty, business and art.

Put simply, Sir David knew everyone, from Fidel Castro – who made him Cuba’s honorary consul in Hong Kong – to Prince Charles and Diana, Princess of Wales. From Margaret Thatcher to Tracey Emin via Russell Crowe, Sir Philip Green, Naomi Campbell and Stephen Fry. And that is to name but a handful.

It would have pleased Sir David to know that thanks to the generosity of the bidders, the Christie’s auction is understood to have raised almost half a million pounds – far more than the £150,000 estimated in the auction catalogue. Yet that is where, to his closest friends, the good news seems to end.

For a growing number have told The Mail on Sunday they now believe Tang died almost penniless. The beautiful £9 million waterfront home in Hong Kong where he and his wife entertained celebrities including the Duchess of York and Bryan Ferry, has gone, along with the house in Belgravia.

His widow Lucy, Lady Tang, is effectively homeless and living with her mother. Said to be shocked at the true state of her late husband’s finances, she has been reduced to auctioning off his most personal possessions in an attempt to salvage something from the wreckage of his debts. It is not even clear how much of this, if any, she will be allowed to keep.

Lady Tang is not the only one to be taken aback. Few of those close to him had any reason to believe that Sir David’s legendary generosity was founded on anything other than his business ingenuity. As one good friend commented ruefully last week, ‘all that glisters is not gold’.

What, then, could have brought the dazzling Tang dynasty to such a state of ruin? One answer is perhaps the extensive medical bills which plagued the final years of his life, including a privately funded liver transplant. Then there were persistent rumours that his early addiction to gambling had never entirely gone away.

Among close friends, it was no secret that Tang was a committed gambler. Also a tireless donor-fundraiser, he was happy to bankroll causes close to his heart, including both charities and friends. It is said, for example, he had been particularly generous to Sarah, Duchess of York (above, with him in 2002)

But what is beyond any doubt is the jaw-droppingly lavish scale on which he led his life, leaving those left behind to ask how on earth he could afford it.

It is an unexpected postscript to an extraordinary life, one which saw a boy who arrived in this country aged 13, speaking not a word of English, rise to become not only a business titan, but arguably the best connected person in British society.

Sir David had certainly started off with money. His journey commenced in 1950s Hong Kong, where his great-grandfather first sought refuge from China and eventually set up a successful bank. It allowed him to build his own house, which became home not only to his wife but also his five concubines.

In turn, his son – David Tang’s grandfather Sir Tang Shiu-kin – would become a prominent Hong Kong businessman who founded the Kowloon Motor Bus company and was later knighted by a grateful British Empire. Tang’s father William, meanwhile, moved to the UK with his family, becoming a restaurateur. On Sir Tang’s death in 1986, David is believed to have inherited around £5 million.

A natural polymath, Tang, who studied law and philosophy at King’s College London, was a brilliant pianist and literature-devouring autodidact with an almost encyclopaedic knowledge, a man capable of completing The Times crossword in minutes.

He was a natural entrepreneur, too, and in 1991 he had the idea that apparently opened the way to a fortune of his own: Tang opened The China Club in the penthouse of the monumental former Bank of China building in Hong Kong.

In recent years, a £1.5 million tax bill handed out by HMRC, in response to Tang overstaying his ‘non-dom’ status in the UK by one day, suggested he was not fully in control of his finances. (Above, with Pippa Middleton in 2013)

A few years later, he founded the upmarket fashion label Shanghai Tang, a brand of ‘modern chinoiserie’, which proved eminently marketable.

Further branches followed, as did a diverse business empire. Tang would ultimately oversee interests including oil exploration in China, gold mining in Africa and Australia and a franchise for Cuban cigars for Canada and Asia which meant that every cigar sold there gave him a cut. Today, China Tang, the restaurant he founded in London’s Dorchester hotel, remains a favourite of A-listers and celebrities.

With the wealth came a life of energetic socialising. Tang forged connections which encompassed all classes, generations and political affiliations and he treated all of them with the same mischievous bonhomie and occasional hauteur, dispensing expletive-laden witticisms in a voice which oscillated between Wodehousian Englishness to heavily accented Cantonese.

He was legendarily generous, placing his houses and drivers at friends’ disposal and entertaining lavishly: Tang would never allow anyone else to pick up the tab and thought nothing of spending tens of thousands on a whim.

One typical Tang gesture is recalled by author Simon Winchester, who met Tang in the 1980s. ‘I was in London and David was in Hong Kong. He phoned up and said, “I am bored, let’s go to Florence.” So he flew to London and me, Lucy and David then flew on to Florence.

‘We were staying at some luxury hotel like the Excelsior for two or three days and then David said, “I would like to go to Cannes” so he got some incredibly expensive car that took two credit cards to hire. We drove up to Cannes and he paid for absolutely everything on the trip.’

Interior designer Joanna Wood, who owns a shop in Belgravia and who knew him both as a friend and client for more than a decade, told The Mail on Sunday that the true state of his finances came as a complete revelation.

‘I really had no idea,’ she said. ‘He always gave the appearance of being very generous and having plenty of staff and money. I feel very sorry for Lucy. I don’t think she knew. If his own wife didn’t know, then how the hell should I?’

It is typical of Tang’s fondness for ostentation that when he met Lucy Wastnage in 1990 – he had a previous marriage by which he has a grown-up son and daughter – their first date was at a cinema where he had bought every seat in the house to guarantee they would be alone.

Yet he was not all surface, but a tireless donor-fundraiser too, happy to bankroll causes close to his heart, including both charities and friends. It is said, for example, he had been particularly generous to Sarah, Duchess of York.

Away from the public gaze, there was another source of expenditure, too: among close friends, it was no secret that Tang was a committed gambler. The subject was raised in 2011 when Tang was interviewed by Kate Moss for Vogue.

‘I’ve heard rumours you like to gamble,’ she said. ‘Have you lost everything before?’

‘Oh yes!’ he replied. ‘I lost everything on one bet, because I thought I’d get it back. This was back in 1970 and I lost my flat.’

Stephen Fry once described Tang as a gambler ‘capable of losing £250,000 in one night’ while Simon Winchester recalls how, on their trip to Cannes, one destination was a large hotel casino. ‘David just peeled off something like $1,000 and said to me, “Put it on any number you like.” It was the roulette table and I put it on 23 and incredibly I won $35,000.

‘I said to David that it was his money but he would not take it. In the end, we agreed that he took $30,000 and I got $5,000.’

In recent years, a £1.5 million tax bill handed out by HMRC, in response to Tang overstaying his ‘non-dom’ status in the UK by one day, suggested he was not fully in control of his finances.

Then, two years ago, came a devastating blow. Sir David discovered he had liver cancer – a particularly grim diagnosis for a man who had an exceptionally rare blood type which left him unable to obtain a new liver in this country.

Late in 2016, he travelled to Kunming in southern China, known as the country’s transplant capital, where he received a new organ.

‘Nobody asked any questions about how they found one so quickly,’ one close friend, who asked not to be named, said. The trip cost thousands and, along with the mounting medical bills when he returned to the UK, doubtless played a part in Tang’s financial unravelling.

Today, The Mail on Sunday has established that few if any of Sir David’s assets remain. He never owned the cigar business – it is said to have been based on no more than a handshake with Fidel – while the brands bearing his name were relinquished some time ago. He only rented the small house in Hyde Park that he shared with his wife towards the end.

And when, in an act of generosity, his friend the restaurateur and club owner Richard Caring made enquiries about purchasing Sir David’s restaurant, China Tang at The Dorchester, he found to his astonishment it had been sold some time previously.

Yet both the opulence and the generosity remained with Sir David until the end.

Indeed, he had planned to leave this life much as he had lived it: with a lavish party. By now desperately ill and sequestered in London’s Royal Marsden Hospital with just months to live, he spent his final weeks last year planning a grand ‘farewell to life party’ at The Dorchester in early September.

Sadly he never made it, passing away at the end of August, amid a legion of loving tributes from friends. ‘RIP dear friend Sir David Tang, the privilege was mine,’ wrote Russell Crowe in a tweet. ‘Witty, charming, intellectual, salacious, hilarious, loving and funny as f***.’

‘There will never be another like you,’ added supermodel Naomi Campbell. Few would disagree, although many will today be asking just how well they really knew him.