Number 2-8a Rutland Gate is an extraordinary property, by anyone’s standards. Built in the Regency style and slathered in white stucco, it is seven storeys high, measures 62,000 square feet, boasts 45 rooms and has sweeping views of London’s Hyde Park through 68 of its 116 windows – all of which sport bulletproof glass.

So it seems rather a shame that, for the past three years, the only resident of this gargantuan Knightsbridge property has been a very cheerful and heavily-bearded Swede called Anders Fernstedt.

Even more so, that 57-year-old Anders – who has a penchant for fine bedding and top-end tweeds, spends a lot of time chatting to the swans in Hyde Park and cycles everywhere – doesn’t actually live inside the building.

‘Oh no, I’ve never been in!’ he tells me, looking horrified. ‘That wouldn’t feel right at all. No, no, no.’

Instead, homeless Anders lives in a cosy nest of duvets, eiderdowns and Hungarian goose down pillows under the property’s grand portico. Where, for company, he has a mountain of dog-eared teddies, toys, games, an awful lot of flowers in vases and a wardrobe full of some surprisingly smart clothes, many donated by his very upmarket neighbours.

They also bring him food, bits of furniture they think he might like and smart leather shoes, but he insists: ‘I never ask for anything.’ The neighbours like him – ‘he’s a wonderful Swedish cove,’ says one dog walker – and take pleasure in the fact that at least someone is getting use out of such a magnificent building.

Because no one around here has any recollection of the current owners ever visiting, let alone staying a single night in their palatial pad. Certainly not since 2020, when the property market was sent into a frenzy by the news that someone had paid a staggering £210million, making it Britain’s most expensive home at the time.

And if that wasn’t enough, the elusive new owner also secured planning permission to extend it – it seems the 62,000 square feet wasn’t quite big enough – with a gigantic spa, Olympic-sized swimming pool, two-storey underground car park, triple-height ballroom and vaulted rooftop conservatory that could open up to the London sky.

But that work never went ahead – and no one will be moving in any time soon.

The buyer, Hui Ka Yan, was founder of Chinese property development giant Evergrande, and was said to have amassed a fortune of around £30billion, including private jets, football clubs and grandiose properties.

But barely a year after he’d splurged so lavishly on Rutland Gate, Evergrande went bust with debts of £225billion precipitating a nationwide property crash in China. Hui was detained, fined £4.8million and vanished from public view.

This month, however, he pleaded guilty in Shenzhen to a slew of charges including bribery and misuse of funds and is now facing a lifetime in prison, rather than enjoying the views of Hyde Park.

But the crux of the Rutland Gate dilemma isn’t lying in a prison in south-east China. In fact, Hui can’t even sell the mansion to pay debts, because when he bought it through a British Virgin Islands Company – naturally – the name on the deeds was that of his then wife, Ding Yumei, a Canadian national.

And it turns out that, right now, she can’t sell it either, because since the divorce and a mad spending spree around the world, her assets have been frozen.

So there it sits, a stone’s throw from the Royal Albert Hall – dirty, derelict and driving the local residents bananas.

‘We can’t bear seeing properties empty, particularly buildings like this – apparently after Buckingham Palace, it’s London’s biggest private home!’ says an immaculately turned-out dog walker. ‘So at least Anders provides some life and colour.’

It’s hard to imagine anyone actually living in it. Not just because it’s so ridiculously large and the endless dirty windows are so blank and looming. There isn’t even a garden, for goodness sake – no wonder Hui and Ding wanted that conservatory extension. But it was never meant to be a single dwelling.

Originally built as four terraced houses in the 19th century, the block was rebuilt in the 1980s by YRM – a firm of architects better known for designing Gatwick Airport and the Sizewell B nuclear power station in Suffolk – and its colossal size and ostentatious location immediately appealed to uber-rich foreigners with more money than sense.

First, was Lebanese construction billionaire and politician Rafic Hariri, who bought the entire plot and had the four houses knocked into one giant mansion. He added endless sweeping staircases and state rooms, and festooned the interiors in golf leaf and glittering chandeliers.

When he died in 2005 – blown up on a Beirut street a year after resigning as Lebanon’s prime minister – his son Saad sold the property to an elderly Saudi crown prince, Sultan bin Abdulaziz, who in turn added 24 marble bathrooms with solid gold taps, more gold leaf, handmade wallpaper, and a Louis XV Pompadour fireplace before he died in 2011.

Neither spent much time actually living there, but they loved having such a posh London foothold in their portfolios.

According to Trevor Abrahmsohn of Glentree Estates, it is all about the prestige. ‘To have a significant property in London is a badge of honour,’ he explains. ‘If you don’t have your second or third property in London then you haven’t arrived.’ The neighbours put it less delicately. ‘They dump their money here so they have a safety blanket in case things go wrong in their countries,’ says Melville Haggard, chairman of the Knightsbridge Association. ‘We really object to places being bought and not used. It happens all over, but this is an entire block! It’s a white elephant.’

So while they all like Anders and bring him offerings, they also like the fact his living there keeps the property’s plight in the news. But how did he end up here? A former journalist, gardener and botanist who trained at the Royal Botanic Garden in Edinburgh, Anders is an only child who has never been married and loves solitude.

He’s tried living in three different council houses (‘dreadful, awful’) on a boat and for a month he camped in a corner of Southgate cricket ground.

He arrived at 2-8a Rutland Gate in 2023 but, unlike the billionaires, wasn’t attracted to its wildly expensive postcode and over-the-top scale. ‘I just liked the fact it was near the swans in Hyde Park. I love swans, I spend hours with them. They call me the swan whisperer,’ he says. ‘

And I could also hear the church bells ringing from the Russian Orthodox church round the corner.’ So he laid out his sleeping bag and mat, gave it a go and immediately felt at peace.

‘Sometimes I am woken by the sound of the Lamborghinis racing at night. Or the clatter of the horses from the Hyde Park barracks, but it’s surprisingly quiet here. Life is so complicated now that you need a doctorate to breathe almost, but I am content. It is very peaceful here.’

Yet Anders is one of few new residents to this exclusive corner of London. With wars raging and the tightening of non-dom regulations, prices in this enclave are down by about 25 per cent since 2022 – yet buyers, especially uber-wealthy ones, remain thin on the ground. Three estate agents on the nearby Brompton Road recently shut up shop.

Since he’s been here, Anders has witnessed just three viewings. ‘The agent was lovely and bought me a cappuccino, what a lovely person,’ he notes. But so is he – even if a terrible hoarder.

The Swede, however, insists his ‘assemblance’ has purpose: the toys are to entertain the local children, the flowers (albeit mostly dead) are to cheer the place up a bit and the bulk of the clutter is to ensure there’s no room for anyone else to join him.

‘One person is fine, but two can turn it into Calais,’ he says, in reference to the migrant camps. ‘And no one wants that.’

Over the years, he’s had a couple of very wet nights when the parasol over his bed wasn’t correctly aligned and just one official complaint, followed up by two policemen visiting to ask him to tidy things up a bit.

‘Like a teenager being asked to clean their room! They were very nice and I’d have made them a cup of tea but I have no electricity.’ Even when the freeze on Ding’s assets is lifted, no one is expecting a good sale – certainly nowhere near the record

£275million paid by billionaire Suneil Setiya for Providence House this month, the massive pile in Chelsea owned by Reform treasurer Nick Candy and his ex-wife Holly Valance.

It also doesn’t help that experts say the maths simply doesn’t work to chop it up into flats or that, inside, it has been stripped bare. All the ornate fixtures and fittings are gone – including all the solid gold taps, sinks and 27 gold-plated waste bins and tissue boxes – which were sold off by the Saudi prince’s family in a 1,189-lot auction in 2015.

‘I’ve had a look around and it’s completely stripped bare. Desolate. Even the fireplaces!’ says Melville Haggard of the residents association.

That means a four-to-six year refurbishment project would be necessary and, according to Trevor Abrahmsohn, today’s high-end client has no interest in that. ‘They want perfection. They want instant gratification. So I’d expect if they got a price in the £120million to £140million range, they’d grab it.’

If and when it is finally sold, Anders will, of course, move on. But for now, he’s astonished he’s been allowed to stay so long and received so much kindness and love. Having met him, I am not.

Yes, his set-up is messy and unconventional but he is fantastically warm, friendly, very clean, utterly charming and an active part of his community. When the place finally sells, the new owner might take a leaf out of his book.